CVE-2026-67353 (Medium) detected in guzzlehttp/guzzle-7.10.0

[mend-bolt-for-github]

CVE-2026-67353 - Medium Severity Vulnerability

Vulnerable Library - guzzlehttp/guzzle-7.10.0

Guzzle is a PHP HTTP client library

Library home page: https://api.github.com/repos/guzzle/guzzle/zipball/b51ac707cfa420b7bfd4e4d5e510ba8008e822b4

Dependency Hierarchy:

• ❌ guzzlehttp/guzzle-7.10.0 (Vulnerable Library)

Found in HEAD commit: 81f84f058af0cbca57ee22476557ded21c6813aa

Found in base branch: master

Vulnerability Details

guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the CookieJar that accepts unlimited Set-Cookie header fields with no size restrictions. Attackers can return many large cookies from a malicious server, causing Guzzle to store excessive data in memory and generate oversized Cookie headers that fail in handlers or destination servers.

Publish Date: 2026-08-01

URL: CVE-2026-67353

CVSS 3 Score Details (5.3)

Base Score Metrics:

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

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-f283-ghqc-fg79

Release Date: 2026-08-01

Fix Resolution: guzzlehttp/guzzle - 7.15.1,https://github.com/guzzle/guzzle.git - 7.15.1

---

Step up your Open Source Security Game with Mend here