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
This advisory covers three security vulnerabilities in the python-urllib3 package affecting Red Hat Enterprise Linux 8.8. CVE-2025-66418 describes an unbounded decompression chain that can cause resource exhaustion. CVE-2025-66471 involves improper handling of highly compressed data in the streaming API. CVE-2026-21441 details a bypass of the decompression-bomb safeguard when following HTTP redirects in the streaming API. These issues can lead to denial of service or resource exhaustion conditions. Red Hat has issued updated python-urllib3 packages (version 1.24.2-5.el8_8.3) that fix these vulnerabilities.
Potential Impact
The vulnerabilities can cause resource exhaustion or denial of service due to unbounded decompression chains or bypass of decompression safeguards in the urllib3 library. This can affect applications relying on urllib3 for HTTP requests, potentially leading to degraded service or crashes. No known exploits in the wild have been reported. The security impact is rated as high by Red Hat.
Mitigation Recommendations
Red Hat has released updated python-urllib3 packages (version 1.24.2-5.el8_8.3) for Red Hat Enterprise Linux 8.8 variants that address these vulnerabilities. Users should apply these official security updates promptly. For detailed update instructions, refer to the Red Hat advisory at https://access.redhat.com/articles/11258. No additional mitigations are specified or required beyond applying the provided 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
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory covers three security vulnerabilities in the python-urllib3 package affecting Red Hat Enterprise Linux 8.8. CVE-2025-66418 describes an unbounded decompression chain that can cause resource exhaustion. CVE-2025-66471 involves improper handling of highly compressed data in the streaming API. CVE-2026-21441 details a bypass of the decompression-bomb safeguard when following HTTP redirects in the streaming API. These issues can lead to denial of service or resource exhaustion conditions. Red Hat has issued updated python-urllib3 packages (version 1.24.2-5.el8_8.3) that fix these vulnerabilities.
Potential Impact
The vulnerabilities can cause resource exhaustion or denial of service due to unbounded decompression chains or bypass of decompression safeguards in the urllib3 library. This can affect applications relying on urllib3 for HTTP requests, potentially leading to degraded service or crashes. No known exploits in the wild have been reported. The security impact is rated as high by Red Hat.
Mitigation Recommendations
Red Hat has released updated python-urllib3 packages (version 1.24.2-5.el8_8.3) for Red Hat Enterprise Linux 8.8 variants that address these vulnerabilities. Users should apply these official security updates promptly. For detailed update instructions, refer to the Red Hat advisory at https://access.redhat.com/articles/11258. No additional mitigations are specified or required beyond applying the provided 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-2026:2718
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-66471","CVE-2026-21441"]
Threat ID: 6a16096be29bf47b50630e4d
Added to database: 05/26/2026, 20:58:19 UTC
Last enriched: 08/17/2026, 17:45:09 UTC
Last updated: 09/10/2026, 19:36:51 UTC
Views: 101
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