CVE-2026-82209

Name	CVE-2026-82209
Description	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`).
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
curl (PTS)	bookworm	7.88.1-10+deb12u15	vulnerable
	bookworm (security)	7.88.1-10+deb12u5	vulnerable
	trixie	8.14.1-2+deb13u5	vulnerable
	forky	8.21.0-2	vulnerable
	sid	8.22.0-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
curl	source	(unstable)	8.22.0-1

Notes

[trixie] - curl <no-dsa> (Minor issue)
[bookworm] - curl <postponed> (Minor issue)
https://curl.se/docs/CVE-2026-82209.html
Introduced with: https://github.com/curl/curl/commit/e77b5b7453c1e8ccd7ec0816890d98e2f392e465 (curl-7_46_0)
Fixed by: https://github.com/curl/curl/commit/95c1e8915dce64606bd753fd47fc0bd236e31cd6 (curl-8_22_0)