Bug 2564253 (CVE-2026-61846)

Summary:	CVE-2026-61846 crass: crass: Denial of Service via deeply nested CSS structures
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, dmayorov, ehelms, eshamard, jlledo, jpasqual, juwatts, jvasik, kaycoth, lblicha, mhulan, ogajduse, osousa, pantinor, rblanco, rchan, smallamp, tsedmik, zhunting
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in crass. The CSS parser is vulnerable to a Denial of Service (DoS) because it recursively processes simple blocks and functions without enforcing a depth limit. A remote attacker can supply a specially crafted CSS input containing deeply nested structures to trigger stack exhaustion or excessive memory consumption, causing the application to crash.	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 2026-10-30 19:17:52 UTC

Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.