SB2026011705 - Debian update for python-urllib3
Published: January 17, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Protection Mechanism Failure (CVE-ID: CVE-2025-50181)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to incorrect implementation of the Redirect object when handling redirects and retries. A remote attacker can force the library to follow redirects even if explicitly disabled with PoolManager.
2) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2025-66418)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to missing limits on the number of links in the decompression chain when handling gzip or zstd data in the server response. A malicious server can send a response with a large amount of links and cause high CPU load, leading to a denial of service condition.
3) Improper handling of highly compressed data (CVE-ID: CVE-2026-21441)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to the application does not properly handle highly compressed data when sending HTTP redirect responses. A remote attacker can multiple large requests to the application, consume all available CPU and memory resources and perform a denial of service attack.
Remediation
Install update from vendor's website.