Red Hat Security Advisory: python3.12-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-2026:1226 addresses three vulnerabilities in the python3.12-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 bypass of decompression-bomb safeguards in the streaming API when following HTTP redirects. These vulnerabilities affect Red Hat Enterprise Linux 8 versions using python3.12-urllib3 version 1.26.19-2.el8_10. The advisory provides updated packages to remediate these issues.
Potential Impact
These vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data, potentially impacting availability. The decompression-bomb safeguard bypass could allow attackers to circumvent protections designed to prevent denial-of-service conditions caused by maliciously crafted compressed data. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released updated python3.12-urllib3 packages (version 1.26.19-2.el8_10) for Red Hat Enterprise Linux 8 that address these vulnerabilities. Users should apply these updates promptly following Red Hat's published guidance at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the official patches.
Red Hat Security Advisory: python3.12-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
pkg:rpm/redhat/python3.12-urllib3Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Red Hat security advisory RHSA-2026:1226 addresses three vulnerabilities in the python3.12-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 bypass of decompression-bomb safeguards in the streaming API when following HTTP redirects. These vulnerabilities affect Red Hat Enterprise Linux 8 versions using python3.12-urllib3 version 1.26.19-2.el8_10. The advisory provides updated packages to remediate these issues.
Potential Impact
These vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data, potentially impacting availability. The decompression-bomb safeguard bypass could allow attackers to circumvent protections designed to prevent denial-of-service conditions caused by maliciously crafted compressed data. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released updated python3.12-urllib3 packages (version 1.26.19-2.el8_10) for Red Hat Enterprise Linux 8 that address these vulnerabilities. Users should apply these updates promptly following Red Hat's published guidance at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated 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-2026:1226
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-66471","CVE-2026-21441"]
Threat ID: 6a16096de29bf47b506340fb
Added to database: 05/26/2026, 20:58:21 UTC
Last enriched: 08/10/2026, 17:58:15 UTC
Last updated: 09/10/2026, 22:04:10 UTC
Views: 87
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