medium5.3
CVE-2026-67339
guzzlehttp/guzzle versions before 7.14.2 fail to properly isolate Proxy-Authorization headers from origin servers in cURL handlers.
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | guzzlehttp/guzzle | < 7.14.2 | 7.14.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-94pj-82f3-465w
- https://github.com/guzzle/guzzle/security/advisories/GHSA-94pj-82f3-465w
- https://github.com/guzzle/guzzle/pull/3876
- https://github.com/guzzle/guzzle/commit/9e4580d4b9981e903dc6323fe37f50a96e85b05e
- https://github.com/guzzle/guzzle/releases/tag/7.14.2
- https://nvd.nist.gov/vuln/detail/CVE-2026-67339
- https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-proxy-authorization-header-disclosure