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GHSA-3GV6-G396-9V4R

Vulnerability from github – Published: 2026-03-27 18:31 – Updated: 2026-06-11 00:32
VLAI
Summary
Undertow is Vulnerable to HTTP Request/Response Smuggling
Details

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending \r\r\r as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.

Severity
8.7 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.undertow:undertow-parent"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.3.23.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-28367"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-31T23:13:55Z",
    "nvd_published_at": "2026-03-27T17:16:27Z",
    "severity": "HIGH"
  },
  "details": "A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\\r\\r\\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.",
  "id": "GHSA-3gv6-g396-9v4r",
  "modified": "2026-06-11T00:32:03Z",
  "published": "2026-03-27T18:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28367"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:25125"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:25126"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-28367"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2443260"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/undertow-io/undertow"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Undertow is Vulnerable to HTTP Request/Response Smuggling"
}



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