CVE-2026-128069

Description

rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. Before 1.7.2, the HTML4 and HTML5 variants of Rails::HTML::SafeListSanitizer reuse one Rails::HTML::PermitScrubber across calls and mutate its tags and attributes without synchronization. In a multithreaded process, concurrent sanitize calls using different tags: or attributes: options can interleave and cause one call to use the other call's allowlist. If a permissive call admits a script element or event-handler attribute, output expected to be sanitized under a stricter policy can retain it and cause cross-site scripting when rendered. Applications that are single-threaded, use one identical allowlist everywhere, or provide a separate scrubber: are not affected. This issue is fixed in version 1.7.2.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 4.7CVSS 3.1, Mediumfrom the CNA (GitHub_M)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-79
• CWE-362

References

• https://github.com/rails/rails-html-sanitizer/security/advisories/GHSA-h7wh-q2qr-458cx_refsource_CONFIRM
• https://github.com/rails/rails-html-sanitizer/issues/228x_refsource_MISC
• https://github.com/rails/rails-html-sanitizer/commit/15f764c3563d5dd9b97ad32eaa7454577ccec4b9x_refsource_MISC
• https://github.com/rails/rails-html-sanitizer/releases/tag/v1.7.2x_refsource_MISC