CVE-2026-53606: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in apostrophecms sanitize-html
ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Versions of sanitize-html prior to 2.17.5 use `allowedSchemesAppliedToAttributes` (default: `['href', 'src', 'cite']`) to gate the `naughtyHref()` function that blocks dangerous URI schemes like `javascript:` and `vbscript:`. The HTML specification defines 10+ attributes that accept URIs (`action`, `formaction`, `data`, `poster`, `background`, `ping`, `xlink:href`, `dynsrc`, `lowsrc`), but none of these are included in the default gate list. When a developer allows any of these attributes in their configuration, `javascript:` URIs pass through completely unmodified, enabling XSS. Version 2.17.5 patches the issue.
AI Analysis
Technical Summary
The sanitize-html package used by ApostropheCMS versions before 2.17.5 uses a default list of attributes ('href', 'src', 'cite') to gate the function that blocks dangerous URI schemes such as 'javascript:' and 'vbscript:'. However, the HTML specification includes over 10 attributes that accept URIs, such as 'action', 'formaction', 'data', and others, which are not included in this default gate list. If developers enable these additional attributes in their sanitize-html configuration, malicious javascript: URIs can bypass the filter, leading to cross-site scripting (CWE-79). This vulnerability is addressed in sanitize-html version 2.17.5.
Potential Impact
This vulnerability allows an attacker to inject malicious javascript: URIs into HTML attributes that are not properly sanitized, potentially enabling cross-site scripting attacks. The impact includes limited confidentiality and integrity loss, with no direct availability impact. Exploitation requires user interaction and low privileges, but can lead to script execution in the context of the affected web application.
Mitigation Recommendations
Upgrade sanitize-html to version 2.17.5 or later, where this issue is fixed. There is no indication of alternative mitigations or temporary fixes. Developers should review their sanitize-html configurations to ensure only safe attributes are allowed and that the latest version is used.
CVE-2026-53606: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in apostrophecms sanitize-html
Description
ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Versions of sanitize-html prior to 2.17.5 use `allowedSchemesAppliedToAttributes` (default: `['href', 'src', 'cite']`) to gate the `naughtyHref()` function that blocks dangerous URI schemes like `javascript:` and `vbscript:`. The HTML specification defines 10+ attributes that accept URIs (`action`, `formaction`, `data`, `poster`, `background`, `ping`, `xlink:href`, `dynsrc`, `lowsrc`), but none of these are included in the default gate list. When a developer allows any of these attributes in their configuration, `javascript:` URIs pass through completely unmodified, enabling XSS. Version 2.17.5 patches the issue.
CVSS v3.1
Score 5.4medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The sanitize-html package used by ApostropheCMS versions before 2.17.5 uses a default list of attributes ('href', 'src', 'cite') to gate the function that blocks dangerous URI schemes such as 'javascript:' and 'vbscript:'. However, the HTML specification includes over 10 attributes that accept URIs, such as 'action', 'formaction', 'data', and others, which are not included in this default gate list. If developers enable these additional attributes in their sanitize-html configuration, malicious javascript: URIs can bypass the filter, leading to cross-site scripting (CWE-79). This vulnerability is addressed in sanitize-html version 2.17.5.
Potential Impact
This vulnerability allows an attacker to inject malicious javascript: URIs into HTML attributes that are not properly sanitized, potentially enabling cross-site scripting attacks. The impact includes limited confidentiality and integrity loss, with no direct availability impact. Exploitation requires user interaction and low privileges, but can lead to script execution in the context of the affected web application.
Mitigation Recommendations
Upgrade sanitize-html to version 2.17.5 or later, where this issue is fixed. There is no indication of alternative mitigations or temporary fixes. Developers should review their sanitize-html configurations to ensure only safe attributes are allowed and that the latest version is used.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-09T19:39:52.404Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a2c758ce617e2d834c30b80
Added to database: 06/12/2026, 21:09:32 UTC
Last enriched: 06/19/2026, 22:19:52 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 90
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