CVE-2026-67339 — MEDIUM (5.3)

Vulnerability Description

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.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-200

References

FAQ

What is CVE-2026-67339?

CVE-2026-67339 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...

How severe is CVE-2026-67339?

CVE-2026-67339 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-67339?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.