CVE-2026-67339 PUBLISHED

guzzlehttp/guzzle before 7.14.2 Proxy-Authorization Header Disclosure

Assigner: VulnCheck
Reserved: 29.07.2026 Published: 01.08.2026 Updated: 01.08.2026

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 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	guzzle
Product	guzzle
Versions	Default: unaffected affected from 0 to 7.14.2 (excl.) Version 7.14.2 is unaffected

CVE-2026-67339 PUBLISHED

guzzlehttp/guzzle before 7.14.2 Proxy-Authorization Header Disclosure

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Problem Types