What is CVE-2026-67339?

CVE-2026-67339 is a medium-severity vulnerability in Guzzle, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-08-01.

How severe is CVE-2026-67339?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Information disclosure in Guzzle

CVE-2026-67339

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, byp…

Vulnerability class: Information Disclosure

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Guzzle — versions 0, 7.14.2

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-67339?: CVE-2026-67339 is a medium-severity vulnerability in Guzzle, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-08-01.
How severe is CVE-2026-67339?: Medium severity. CVSS v3 base score is 5.3 out of 10.