Bug 2572678 (CVE-2026-126193)

Summary:	CVE-2026-126193 soupsieve: Soup Sieve: Denial of Service via deeply nested CSS pseudo-class selectors
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:	akhatavk, anpicker, aos-team-art-private, aprice, aruklets, asdas, bcaton, cmyers, crizzo, dkeler, dnakabaa, doconnor, dpaolell, ebourniv, eglynn, hasun, jdelft, jfula, jjoyce, jlanda, jowilson, jpretori, jsamir, jschluet, jupierce, kaycoth, kshier, lcouzens, lgarciaa, lhh, mbiarnes, mburns, mgarciac, nyancey, oezr, ometelka, pakotvan, ppalepu, ppostler, prdhamdh, ptisnovs, rbobbitt, sbunciak, sghai, shudeshp, sidsharm, simaishi, stcannon, sthirugn, suppawar, syedriko, thason, vlaad, xdharmai, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Soup Sieve. A remote attacker can trigger a localized Denial of Service (DoS) by providing deeply nested Cascading Style Sheets (CSS) pseudo-class selectors to applications that accept untrusted input. Processing these nested selectors exceeds the parser's recursion limit, resulting in an unhandled exception that can cause the affected request or task to fail.	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 2026-11-12 17:21:41 UTC

Soup Sieve is a CSS selector library for Beautiful Soup. From 0.4 until 3.0, deeply nested CSS pseudo-class selectors can cause recursive parsing to exceed Python’s recursion limit and raise  RecursionError . Applications accepting untrusted selectors may experience failure of the affected request or task if the exception is not handled. The demonstrated behavior is recoverable and does not establish an interpreter crash or persistent service-wide denial of service. This vulnerability is fixed in version 3.0.