Red Hat Security Advisory: python3.11-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-2026:1712 reports three vulnerabilities in the python3.11-urllib3 package: 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; and CVE-2026-21441 describes a decompression-bomb safeguard bypass when following HTTP redirects in the streaming API. These flaws relate to decompression logic and resource management within urllib3, potentially allowing attackers to exhaust system resources. The advisory provides updated python3.11-urllib3 packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants to remediate these issues.
Potential Impact
The vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data, potentially causing denial of service conditions. The decompression-bomb safeguard bypass may allow attackers to circumvent protections designed to prevent resource exhaustion attacks when HTTP redirects are followed in streaming scenarios. No known exploits in the wild have been reported at the time of this advisory.
Mitigation Recommendations
Red Hat has released updated python3.11-urllib3 packages for Red Hat Enterprise Linux 9.4 Extended Update Support that address these vulnerabilities. Users should apply these official updates promptly to remediate the issues. For detailed update instructions, refer to the Red Hat article at https://access.redhat.com/articles/11258. No alternative mitigations or workarounds are specified in the advisory.
Red Hat Security Advisory: python3.11-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
The Red Hat Security Advisory RHSA-2026:1712 reports three vulnerabilities in the python3.11-urllib3 package: 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; and CVE-2026-21441 describes a decompression-bomb safeguard bypass when following HTTP redirects in the streaming API. These flaws relate to decompression logic and resource management within urllib3, potentially allowing attackers to exhaust system resources. The advisory provides updated python3.11-urllib3 packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants to remediate these issues.
Potential Impact
The vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data, potentially causing denial of service conditions. The decompression-bomb safeguard bypass may allow attackers to circumvent protections designed to prevent resource exhaustion attacks when HTTP redirects are followed in streaming scenarios. No known exploits in the wild have been reported at the time of this advisory.
Mitigation Recommendations
Red Hat has released updated python3.11-urllib3 packages for Red Hat Enterprise Linux 9.4 Extended Update Support that address these vulnerabilities. Users should apply these official updates promptly to remediate the issues. For detailed update instructions, refer to the Red Hat article at https://access.redhat.com/articles/11258. No alternative mitigations or workarounds are specified in the advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:1712
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-66471","CVE-2026-21441"]
Threat ID: 6a16096ce29bf47b50632aa9
Added to database: 05/26/2026, 20:58:20 UTC
Last enriched: 08/10/2026, 17:49:33 UTC
Last updated: 09/10/2026, 19:36:51 UTC
Views: 58
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