CVE-2026-67355: Guzzle

Medium severity, CVSS 5.9. EPSS: 0.4% chance of exploitation in the next 30 days.

guzzlehttp/guzzle versions before 7.15.1 fail to preserve host-only cookie scope, storing the request host in the Domain field instead of marking cookies as host-only. Attackers controlling child hosts can receive host-only cookies intended only for parent hosts, potentially disclosing session identifiers and authorization tokens when the same cookie jar is reused across trust boundaries.

Affected products

• Guzzle Guzzle: before 7.15.1 (fixed in 7.15.1)

Published 2026-08-01. Last modified 2026-10-08.