🛡️ CVE-2025-66418 on Ubuntu — python-pip

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2025-66418 as tracked by Ubuntu, for the package python-pip. The fix is available in version 2.5.0-1ubuntu1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software and timeline

Affected software: python-pip and python-urllib3 (fixed in 2.5.0-1ubuntu1). Published on 5 December 2025 and last revised on 29 May 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
www.openwall.com (Report)
github.com (Report)
ubuntu.com (Advisory)
ubuntu.com (Advisory)
ubuntu.com (Advisory)

CVE-2025-66418 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2025-12-05
Updated 2026-08-12
Modified 2026-05-29
Fix URL N/A

Affected Packages

Software From version Fixed in
python-pip — —
python-urllib3 — 2.5.0-1ubuntu1

Site Security Check

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UBUNTU-CVE-2025-66418 is rated CVSS 8.0 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

More UBUNTU CVE 2025 advisories

Part of UBUNTU CVE 2025 in the advisory index.