CVE-2026-55767

Summary: Guzzle 7.x before 7.12.1 is vulnerable to cookie domain handling flaws in CookieJar. dot-only Domain attributes (e.g., Domain=., Domain=.., or whitespace-padded variants) are normalized to an empty domain, and the code path that rejects only an empty domain still allows it to match any h...

GHSA-CWXW-98QJ-8QJX guzzlehttp/guzzle: Dot-Only Cookie Domains Match All Hosts

Impact CookieJar incorrectly accepts cookies with a dot-only Domain attribute, such as Domain=., Domain=.., Domain=..., and whitespace-padded variants such as Domain= . . In affected versions, SetCookie::matchesDomain removes leading dots from the cookie domain, normalizing dot-only values to the...