Bug 2529207 (CVE-2026-82209)

Summary:	CVE-2026-82209 curl: libcurl: Information disclosure via improper Public Suffix List boundary check
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	akhatavk, anthomas, aos-team-art-private, asdas, bbrownin, crizzo, dpaolell, ehelms, ggainey, gtanzill, jbuscemi, jdelft, jpasqual, jupierce, juwatts, kshier, lgarciaa, mbiarnes, mdellweg, mhulan, nmoumoul, osousa, pcreech, ppalepu, ppostler, prdhamdh, rchan, rekumar, rhel-process-autobot, sdawley, sghai, sidsharm, smallamp, stcannon, suppawar, teagle, tmalecek, vlaad, vvoronko, 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 libcurl when libpsl support is enabled. A remote attacker could exploit this vulnerability by setting a `Set-Cookie` header with a `Domain` attribute that explicitly matches a public suffix. This improper handling causes libcurl to save the cookie with a wildcard domain scope, leading to the cookie being inappropriately sent to arbitrary sibling subdomains under the same public suffix. This could result in sensitive information disclosure.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-06 18:01:47 UTC

When libpsl support is enabled, libcurl fails to enforce the Public Suffix
List boundary check when processing a `Set-Cookie` header where the `Domain`
attribute explicitly matches an origin host that is itself a public suffix
(e.g., `Domain=co.uk` set by `co.uk`).

Instead of coercing it into a strict host-only cookie, libcurl saves the
cookie with wildcard domain scope (`.co.uk`). Consequently, the cookie is
inappropriately included in subsequent outbound requests or HTTP redirects to
arbitrary sibling subdomains under the same public suffix (e.g.,
`attacker.co.uk`).