CVEvulnerability
CVE-2025-66418
8.9 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2025-12-05
- Last modified
- 2026-09-25
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 8.9 HIGH — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
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.
Affected configurations
• python urllib3 (>= 1.24 < 2.6.0)
Related
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness