Description

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.

INFO

Published Date :

2025-12-05T16:02:15.271Z

Last Modified :

2025-12-05T18:15:28.505Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2025-66418 vulnerability.

Vendors Products
Python
  • Urllib3
Urllib3
  • Urllib3
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-66418.

URL Resource
https://github.com/urllib3/urllib3/commit/24d7b67eac89f94e11003424bcf0d8f7b72222a8 cve-icon cve-icon cve-icon
https://github.com/urllib3/urllib3/security/advisories/GHSA-gm62-xv2j-4w53 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-66418 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-66418 cve-icon
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CVSS Vulnerability Scoring System

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Detailed values of each vector for above chart.
Attack Vector
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User Interaction
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Integrity Impact
Availability Impact