Common Weakness Enumeration
CWE-116
Allowed-with-ReviewImproper Encoding or Escaping of Output
Abstraction: Class · Status: Draft
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
698 vulnerabilities reference this CWE, most recent first.
CVE-2026-41426 (GCVE-0-2026-41426)
Vulnerability from cvelistv5 – Published: 2026-04-24 19:15 – Updated: 2026-04-25 01:50
VLAI
EPSS
VEX
Title
pretalx: Email injection via unescaped user-controlled placeholders in pretalx mail templates
Summary
pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.
Severity
6.1 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-25 01:50 UTC
CWE
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/pretalx/pretalx/security/advis… | x_refsource_CONFIRM |
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CVE-2026-41318 (GCVE-0-2026-41318)
Vulnerability from cvelistv5 – Published: 2026-04-24 02:57 – Updated: 2026-04-24 18:17
VLAI
EPSS
VEX
Title
AnythingLLM vulnerable to stored DOM XSS in chart caption renderer - LLM-driven prompt injection produces executable HTML via unsanitized renderMarkdown(content.caption) in Chartable component
Summary
AnythingLLM is an application that turns pieces of content into context that any LLM can use as references during chatting. Prior to version 1.12.1, AnythingLLM's in-chat markdown renderer has an unsafe custom rule for images that interpolates the markdown image's `alt` text into an HTML `alt="..."` attribute without any HTML encoding. Every call-site in the app wraps `renderMarkdown(...)` with `DOMPurify.sanitize(...)` as defense-in-depth — except the `Chartable` component, which renders chart captions with no sanitization. The chart caption is the natural-language text the LLM emits around a `create-chart` tool call, so any attacker who can influence the LLM's output — most cheaply via indirect prompt injection in a shared workspace document, or directly if they can create a chart record in a multi-user workspace — can trigger stored DOM-level XSS in every other user's browser when they open that conversation. AnythingLLM chat history is loaded server-side via `GET /api/workspace/:slug/chats` and rendered directly into the chat UI. Version 1.12.1 contains a patch for this issue.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-24 17:24 UTC
CWE
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/Mintplex-Labs/anything-llm/sec… | x_refsource_CONFIRM |
| https://github.com/Mintplex-Labs/anything-llm/com… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mintplex-Labs | anything-llm |
Affected:
< 1.12.1
|
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CVE-2026-40871 (GCVE-0-2026-40871)
Vulnerability from cvelistv5 – Published: 2026-04-21 19:12 – Updated: 2026-04-21 20:36
VLAI
EPSS
VEX
Title
mailcow: dockerized vulnerable to Second Order SQL Injection in quarantine category via API
Summary
mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint stores quarantine_category without validation or sanitization. This value is later used by quarantine_notify.py, which constructs SQL queries using unsafe % string formatting instead of parameterized queries. This results in a delayed (second-order) SQL injection when the quarantine notification job executes, allowing an attacker to inject arbitrary SQL. Using a UNION SELECT, sensitive data (e.g., admin credentials) can be exfiltrated and rendered inside quarantine notification emails. Version 2026-03b fixes the vulnerability.
Severity
7.2 (High)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-21 19:53 UTC
CWE
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/mailcow/mailcow-dockerized/sec… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| mailcow | mailcow-dockerized |
Affected:
< 2026-03b
|
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CVE-2026-40593 (GCVE-0-2026-40593)
Vulnerability from cvelistv5 – Published: 2026-04-18 00:02 – Updated: 2026-04-20 14:56
VLAI
EPSS
VEX
Title
ChurchCRM: Stored XSS in UserEditor.php via Login Name Field
Summary
ChurchCRM is an open-source church management system. In versions prior to 7.2.0, the User Editor (UserEditor.php) renders stored usernames directly into an HTML input value attribute without applying htmlspecialchars(). An administrator can save a username containing HTML attribute-breaking characters and event handlers, which execute in the browser of any administrator who subsequently views that user's editor page, resulting in stored XSS. This issue has been fixed in version 7.2.0.
Severity
4.8 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-20 14:51 UTC
CWE
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/ChurchCRM/CRM/security/advisor… | x_refsource_CONFIRM |
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CVE-2026-40568 (GCVE-0-2026-40568)
Vulnerability from cvelistv5 – Published: 2026-04-21 16:08 – Updated: 2026-04-21 20:37
VLAI
EPSS
VEX
Title
FreeScout Vulnerable to XSS via Mailbox Signature Due to Incomplete HTML Sanitization
Summary
FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function `Helper::stripDangerousTags()` (`app/Misc/Helper.php:568`) uses an incomplete blocklist of only four HTML tags (`script`, `form`, `iframe`, `object`) and does not remove event handler attributes. When a mailbox signature is saved via `MailboxesController::updateSave()` (`app/Http/Controllers/MailboxesController.php:267`), HTML elements such as `<img>`, `<svg>`, and `<details>` with event handler attributes like `onerror` and `onload` pass through sanitization unchanged and are stored in the database. The signature is then rendered as raw HTML via the Blade `{!! !!}` tag in `editor_bottom_toolbar.blade.php:6` and re-inserted into the visible DOM by jQuery `.html()` at `main.js:1789-1790`, triggering the injected event handlers. Any authenticated user with the `ACCESS_PERM_SIGNATURE` (`sig`) permission on a mailbox -- a delegatable, non-admin permission -- can inject arbitrary HTML and JavaScript into the mailbox signature. The payload fires automatically, with no victim interaction, whenever any agent or administrator opens any conversation in the affected mailbox. This enables session hijacking (under CSP bypass conditions such as IE11 or module-weakened CSP), phishing overlays that work in all browsers regardless of CSP, and chaining to admin-level actions including email exfiltration via mass assignment and self-propagating worm behavior across all mailboxes. Version 1.8.213 fixes the issue.
Severity
8.5 (High)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-21 20:32 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/freescout-help-desk/freescout/… | x_refsource_CONFIRM |
| https://github.com/freescout-help-desk/freescout/… | x_refsource_MISC |
| https://github.com/freescout-help-desk/freescout/… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| freescout-help-desk | freescout |
Affected:
< 1.8.213
|
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CVE-2026-40567 (GCVE-0-2026-40567)
Vulnerability from cvelistv5 – Published: 2026-04-21 16:06 – Updated: 2026-04-21 19:17
VLAI
EPSS
VEX
Title
FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables
Summary
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization's address. Version 1.8.213 fixes the issue.
Severity
5.8 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-21 19:17 UTC
CWE
- CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/freescout-help-desk/freescout/… | x_refsource_CONFIRM |
| https://github.com/freescout-help-desk/freescout/… | x_refsource_MISC |
| https://github.com/freescout-help-desk/freescout/… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| freescout-help-desk | freescout |
Affected:
< 1.8.213
|
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CVE-2026-40483 (GCVE-0-2026-40483)
Vulnerability from cvelistv5 – Published: 2026-04-17 23:20 – Updated: 2026-04-20 16:16
VLAI
EPSS
VEX
Title
ChurchCRM: Stored XSS in PledgeEditor.php via Donation Comment Field
Summary
ChurchCRM is an open-source church management system. In versions prior to 7.2.0, the Pledge Editor renders donation comment values directly into HTML input value attributes without escaping via htmlspecialchars(). An authenticated user with Finance permissions can inject HTML attribute-breaking characters and event handlers into the comment field, which are stored in the database and execute in the browser of any user who subsequently opens the pledge record for editing, resulting in stored XSS. This issue has been fixed in version 7.2.0.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-20 16:09 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/ChurchCRM/CRM/security/advisor… | x_refsource_CONFIRM |
| https://github.com/ChurchCRM/CRM/pull/8609 | x_refsource_MISC |
| https://github.com/ChurchCRM/CRM/commit/b3da72a2b… | x_refsource_MISC |
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CVE-2026-40302 (GCVE-0-2026-40302)
Vulnerability from cvelistv5 – Published: 2026-04-17 20:56 – Updated: 2026-04-18 03:07
VLAI
EPSS
VEX
Title
zrok has reflected XSS in GitHub OAuth callback via unsanitized refreshInterval error rendering
Summary
zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, the proxyUi template engine uses Go's text/template (which performs no HTML escaping) instead of html/template. The GitHub OAuth callback handlers in both publicProxy and dynamicProxy embed the attacker-controlled refreshInterval query parameter verbatim into an error message when time.ParseDuration fails, and render that error unescaped into HTML. An attacker can deliver a crafted login URL to a victim; after the victim completes the GitHub OAuth flow, the callback page executes arbitrary JavaScript in the OAuth server's origin. Version 2.0.1 patches the issue.
Severity
6.1 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-18 03:07 UTC
CWE
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/openziti/zrok/security/advisor… | x_refsource_CONFIRM |
| https://github.com/openziti/zrok/releases/tag/v2.0.1 | x_refsource_MISC |
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CVE-2026-40023 (GCVE-0-2026-40023)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:45 – Updated: 2026-04-10 17:29
VLAI
EPSS
VEX
Title
Apache Log4cxx, Apache Log4cxx (Conan), Apache Log4cxx (Brew): Silent log event loss in XMLLayout due to unescaped XML 1.0 forbidden characters
Summary
Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx_1_1xml_1_1XMLLayout.html , in versions before 1.7.0, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in log messages, NDC, and MDC property keys and values, producing invalid XML output. Conforming XML parsers must reject such documents with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.
An attacker who can influence logged data can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity.
Users are advised to upgrade to Apache Log4cxx 1.7.0, which fixes this issue.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-10 17:28 UTC
CWE
- CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4cxx/pull/609 | patch |
| https://logging.apache.org/security.html#CVE-2026-40023 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4cxx/1.7.0/classlog… | related |
| https://lists.apache.org/thread/y15cv3zblg3dfwr5v… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/0… |
Impacted products
3 products
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4cxx |
Affected:
0 , < 1.7.0
(semver)
cpe:2.3:a:apache:log4cxx:*:*:*:*:*:*:*:* |
|
| Apache Software Foundation | Apache Log4cxx (Conan) |
Affected:
0 , < 1.7.0
(semver)
|
|
| Apache Software Foundation | Apache Log4cxx (Brew) |
Affected:
0 , < 1.7.0
(semver)
|
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CVE-2026-40021 (GCVE-0-2026-40021)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:44 – Updated: 2026-04-10 17:35
VLAI
EPSS
VEX
Title
Apache Log4net: Silent log event loss in XmlLayout and XmlLayoutSchemaLog4J due to unescaped XML 1.0 forbidden characters
Summary
Apache Log4net's XmlLayout https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list and XmlLayoutSchemaLog4J https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list , in versions before 3.3.0, fail to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in MDC property keys and values, as well as the identity field that may carry attacker-influenced data. This causes an exception during serialization and the silent loss of the affected log event.
An attacker who can influence any of these fields can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity.
Users are advised to upgrade to Apache Log4net 3.3.0, which fixes this issue.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-10 17:32 UTC
CWE
- CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4net/pull/280 | patch |
| https://logging.apache.org/security.html#CVE-2026-40021 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4net/manual/configu… | related |
| https://lists.apache.org/thread/q8otftjswhk69n3kx… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/0… |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4net |
Affected:
0 , < 3.3.0
(nuget)
cpe:2.3:a:apache:log4net:*:*:*:*:*:*:*:* |
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Mitigation MIT-4.3
Architecture and Design
Strategy: Libraries or Frameworks
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
- Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
Mitigation MIT-27
Architecture and Design
Strategy: Parameterization
- If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
- For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.
Mitigation
Architecture and Design
Implementation
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
Mitigation
Architecture and Design
In some cases, input validation may be an important strategy when output encoding is not a complete solution. For example, you may be providing the same output that will be processed by multiple consumers that use different encodings or representations. In other cases, you may be required to allow user-supplied input to contain control information, such as limited HTML tags that support formatting in a wiki or bulletin board. When this type of requirement must be met, use an extremely strict allowlist to limit which control sequences can be used. Verify that the resulting syntactic structure is what you expect. Use your normal encoding methods for the remainder of the input.
Mitigation
Architecture and Design
Use input validation as a defense-in-depth measure to reduce the likelihood of output encoding errors (see CWE-20).
Mitigation
Requirements
Fully specify which encodings are required by components that will be communicating with each other.
Mitigation
Implementation
When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
CAPEC-104: Cross Zone Scripting
An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security.
CAPEC-73: User-Controlled Filename
An attack of this type involves an adversary inserting malicious characters (such as a XSS redirection) into a filename, directly or indirectly that is then used by the target software to generate HTML text or other potentially executable content. Many websites rely on user-generated content and dynamically build resources like files, filenames, and URL links directly from user supplied data. In this attack pattern, the attacker uploads code that can execute in the client browser and/or redirect the client browser to a site that the attacker owns. All XSS attack payload variants can be used to pass and exploit these vulnerabilities.
CAPEC-81: Web Server Logs Tampering
Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.
CAPEC-85: AJAX Footprinting
This attack utilizes the frequent client-server roundtrips in Ajax conversation to scan a system. While Ajax does not open up new vulnerabilities per se, it does optimize them from an attacker point of view. A common first step for an attacker is to footprint the target environment to understand what attacks will work. Since footprinting relies on enumeration, the conversational pattern of rapid, multiple requests and responses that are typical in Ajax applications enable an attacker to look for many vulnerabilities, well-known ports, network locations and so on. The knowledge gained through Ajax fingerprinting can be used to support other attacks, such as XSS.