CVE-2026-67339

MEDIUM 5.3

guzzlehttp/guzzle before 7.14.2 Proxy-Authorization Header Disclosure

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-200
Vendor	guzzle
Product	guzzle
Published	Aug 1, 2026

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CVSS v3 Breakdown

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

Affected Versions

guzzle / guzzle

0 < 7.14.2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/guzzle/guzzle/security/advisories/GHSA-94pj-82f3-465w vulncheck.com: https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-proxy-authorization-header-disclosure

Credits

🔍 GrahamCampbell