Bug 2528747 (CVE-2026-85008)

Summary:	CVE-2026-85008 undici: undici: Integrity failure due to caching of unsafe HTTP method responses
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abarbaro, akhatavk, alizardo, aos-team-art-private, asdas, ataylor, cdrage, csuconic, dbruscin, dpaolell, dschmidt, eborisov, ehugonne, gbenhaim, gtanzill, gtully, jbuscemi, jchui, jdelft, jhe, jlanda, jsherman, jupierce, kshier, ktsao, kvanderr, lball, lchilton, lgarciaa, mbiarnes, mstipich, nboldt, ngough, niyer, oaljalju, ppalepu, ppostler, prdhamdh, psrna, rexwhite, rgemmell, rgodfrey, rhel-process-autobot, rushinde, sdawley, sfeifer, sghai, sidsharm, simaishi, stcannon, sthirugn, suppawar, tbish, tlavocat, twaugh, veshanka, vlaad, watson-tool-maintainers, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in undici. The cache interceptor incorrectly caches responses to unsafe HTTP methods, such as POST, PUT, or DELETE. A remote attacker can exploit this by providing a cacheable response, leading to subsequent state-changing requests being served from a stale cache entry without reaching the origin. This can result in an integrity failure, where the client's application state is not updated as expected.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2540155, 2540156, 2540153, 2540154
Bug Blocks:

Description OSIDB Bzimport 2026-09-04 17:18:07 UTC

undici's cache interceptor documents that only safe HTTP methods are cached, but its logic to skip caching is built by subtracting the configured methods from the set of safe methods, so an unsafe method such as POST, PUT, or DELETE is never placed in the skip list and instead falls through to the full cache-read path. The response-storage gate also lacked a method check, so a response to an unsafe request that is heuristically cacheable or carries an explicit Cache-Control directive is stored and later replayed from cache. Because response headers from a remote origin are untrusted, an origin can answer once with a cacheable status and then have the client's own subsequent state-changing requests to that path served from the stale cache entry without ever reaching the origin, an integrity failure that occurs under the interceptor's default configuration. This affects undici versions from 7.0.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.