CVE-2026-67339: Guzzle

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

guzzlehttp/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in cURL handlers. Attackers can capture proxy credentials through origin server access logs when requests are redirected, bypassed, or sent through SOCKS proxies that Guzzle misclassifies as direct connections.

Affected products

• Guzzle Guzzle: before 7.14.2 (fixed in 7.14.2)

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