CVE-2025-66418 (High) detected in urllib3-1.26.8-py2.py3-none-any.whl

[mend-bolt-for-github]

CVE-2025-66418 - High Severity Vulnerability

Vulnerable Library - urllib3-1.26.8-py2.py3-none-any.whl

HTTP library with thread-safe connection pooling, file post, and more.

Library home page: https://files.pythonhosted.org/packages/4e/b8/f5a25b22e803f0578e668daa33ba3701bb37858ec80e08a150bd7d2cf1b1/urllib3-1.26.8-py2.py3-none-any.whl

Path to dependency file: /server/requirements.txt

Path to vulnerable library: /server/requirements.txt

Dependency Hierarchy:

• coreapi-2.3.3-py2.py3-none-any.whl (Root Library)
  • requests-2.27.1-py2.py3-none-any.whl
    • ❌ urllib3-1.26.8-py2.py3-none-any.whl (Vulnerable Library)

Found in HEAD commit: f5138814bd6e253a8a5e8826b5a576edb13ed346

Found in base branch: main

Vulnerability Details

urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.24 and prior to 2.6.0, the number of links in the decompression chain was unbounded allowing a malicious server to insert a virtually unlimited number of compression steps leading to high CPU usage and massive memory allocation for the decompressed data. This vulnerability is fixed in 2.6.0.

Publish Date: 2025-12-05

URL: CVE-2025-66418

CVSS 3 Score Details (8.6)

Base Score Metrics:

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

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2025-12-05

Fix Resolution: https://github.com/urllib3/urllib3.git - 2.6.0,urllib3 - 2.6.0

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