Red Hat Security Advisory: python-urllib3 security update
Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Security Fix(es): * urllib3: urllib3: Unbounded decompression chain leads to resource exhaustion (CVE-2025-66418) * urllib3: urllib3 Streaming API improperly handles highly compressed data (CVE-2025-66471) * urllib3: urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API) (CVE-2026-21441) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
The Red Hat Security Advisory RHSA-2026:1726 addresses three vulnerabilities in the python-urllib3 library. CVE-2025-66418 involves an unbounded decompression chain that can cause resource exhaustion. CVE-2025-66471 concerns improper handling of highly compressed data in the urllib3 streaming API. CVE-2026-21441 describes a bypass of the decompression-bomb safeguard when following HTTP redirects using the streaming API. These vulnerabilities could potentially be exploited to exhaust system resources or bypass safeguards designed to prevent decompression bombs. The advisory provides updated packages for Red Hat Enterprise Linux 10.0 Extended Update Support across multiple architectures.
Potential Impact
These vulnerabilities can lead to resource exhaustion due to unbounded decompression chains or bypass of decompression safeguards, potentially impacting system stability or availability. The improper handling of highly compressed data may allow attackers to cause denial-of-service conditions. No known exploits in the wild have been reported. The security impact is rated as Important by Red Hat.
Mitigation Recommendations
Red Hat has released updated python-urllib3 packages (version 1.26.19-2.el10_0.1) that address these vulnerabilities. Users of Red Hat Enterprise Linux 10.0 Extended Update Support should apply these updates promptly. For detailed update instructions, refer to https://access.redhat.com/articles/11258. No additional mitigations are specified beyond applying the official patches.
Red Hat Security Advisory: python-urllib3 security update
Description
Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Security Fix(es): * urllib3: urllib3: Unbounded decompression chain leads to resource exhaustion (CVE-2025-66418) * urllib3: urllib3 Streaming API improperly handles highly compressed data (CVE-2025-66471) * urllib3: urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API) (CVE-2026-21441) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Red Hat Security Advisory RHSA-2026:1726 addresses three vulnerabilities in the python-urllib3 library. CVE-2025-66418 involves an unbounded decompression chain that can cause resource exhaustion. CVE-2025-66471 concerns improper handling of highly compressed data in the urllib3 streaming API. CVE-2026-21441 describes a bypass of the decompression-bomb safeguard when following HTTP redirects using the streaming API. These vulnerabilities could potentially be exploited to exhaust system resources or bypass safeguards designed to prevent decompression bombs. The advisory provides updated packages for Red Hat Enterprise Linux 10.0 Extended Update Support across multiple architectures.
Potential Impact
These vulnerabilities can lead to resource exhaustion due to unbounded decompression chains or bypass of decompression safeguards, potentially impacting system stability or availability. The improper handling of highly compressed data may allow attackers to cause denial-of-service conditions. No known exploits in the wild have been reported. The security impact is rated as Important by Red Hat.
Mitigation Recommendations
Red Hat has released updated python-urllib3 packages (version 1.26.19-2.el10_0.1) that address these vulnerabilities. Users of Red Hat Enterprise Linux 10.0 Extended Update Support should apply these updates promptly. For detailed update instructions, refer to https://access.redhat.com/articles/11258. No additional mitigations are specified beyond applying the official patches.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:1726
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-66471","CVE-2026-21441"]
Threat ID: 6a16096ce29bf47b50632a9a
Added to database: 05/26/2026, 20:58:20 UTC
Last enriched: 08/10/2026, 17:48:46 UTC
Last updated: 09/10/2026, 19:36:51 UTC
Views: 101
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