Bug 2562396 (CVE-2026-116695)

Summary:	CVE-2026-116695 crass: crass: CSS injection via malformed URL token parsing
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akostadi, amasferr, anthomas, dmayorov, ehelms, eshamard, ggainey, jlledo, jpasqual, juwatts, jvasik, kaycoth, mdellweg, mhulan, nmoumoul, osousa, pantinor, pcreech, rblanco, rchan, smallamp, tmalecek, tsedmik
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Crass. When parsing malformed URL tokens containing escaped backslashes, Crass incorrectly treats the closing parenthesis as escaped, retaining style declarations that web browsers interpret as active Cascading Style Sheets (CSS). A remote attacker could supply crafted CSS to an application relying on Crass for sanitization, enabling unauthorized style injection that can lead to sensitive data exfiltration or user interface manipulation.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-10-27 20:23:03 UTC

Crass is a Ruby CSS parser that is compliant with the CSS Syntax Level 3 specification. Prior to 1.0.8, Crass incorrectly treats a closing parenthesis after an escaped backslash as escaped while consuming the remnants of a bad URL. Crass therefore keeps declarations, style rules, or at-rules inside a bad URL token even though a browser treats them as live CSS. A sanitizer that parses untrusted CSS with Crass and reserializes it without rejecting the bad URL can allow CSS used for UI redress, external resource loading, or CSS-based data exfiltration, but this issue does not enable script execution in modern browsers. This issue is fixed in version 1.0.8.