Bug 2573204 (CVE-2026-126063) - CVE-2026-126063 nokogiri: nokogiri: Cross-site scripting via unescaped content in HTML5 serializer
Summary: CVE-2026-126063 nokogiri: nokogiri: Cross-site scripting via unescaped conten...
Keywords:
Status: NEW
Alias: CVE-2026-126063
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-11-13 16:02 UTC by OSIDB Bzimport
Modified: 2026-11-13 16:17 UTC (History)
11 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)

Description OSIDB Bzimport 2026-11-13 16:02:00 UTC 
Nokogiri is an open source XML and HTML library for the Ruby programming language. From 1.12.0 until 1.19.5, the C extension on CRuby and TruffleRuby has a Nokogiri::HTML5 serializer that does not escape text inside noscript elements or angle brackets inside attribute values. When an application sanitizes untrusted HTML with the default parsing options, allows noscript, and sends serialized output to a scripting-enabled browser, the browser can parse markup that Nokogiri did not produce, enabling mutation cross-site scripting. Using parse_noscript_content_as_text: true is the recommended workaround, not the vulnerable default. JRuby is not affected because it does not implement Nokogiri::HTML5. This issue is fixed in version 1.19.5.
Note You need to log in before you can comment on or make changes to this bug.