Red Hat Security Advisory: python3.11-urllib3 security update
This advisory addresses multiple security vulnerabilities in the python3. 11-urllib3 package for Red Hat Enterprise Linux 8. The issues include unbounded decompression chains leading to resource exhaustion, improper handling of highly compressed data in the streaming API, and a decompression-bomb safeguard bypass when following HTTP redirects. These vulnerabilities could potentially be exploited to cause denial of service conditions. Red Hat has released updated packages to fix these issues. The update is rated as having an Important security impact by Red Hat Product Security.
AI Analysis
Technical Summary
The python3.11-urllib3 package in Red Hat Enterprise Linux 8 contains three related vulnerabilities: CVE-2025-66418 involves an unbounded decompression chain that can lead to resource exhaustion; CVE-2025-66471 concerns improper handling of highly compressed data in the urllib3 streaming API; and CVE-2026-21441 allows bypassing the decompression-bomb safeguard when following HTTP redirects in the streaming API. These flaws relate to how urllib3 processes compressed HTTP content, potentially enabling denial of service via resource exhaustion. Red Hat has issued security updates (RHSA-2026:1224) that address these vulnerabilities across multiple architectures and extended life cycle versions of RHEL 8.
Potential Impact
The vulnerabilities can lead to resource exhaustion through unbounded decompression chains or bypassing decompression safeguards, which may cause denial of service conditions in applications using the affected urllib3 streaming API. No known exploits are reported in the wild. The impact is rated as Important by Red Hat, indicating a high severity but not critical.
Mitigation Recommendations
Red Hat has released updated python3.11-urllib3 packages for Red Hat Enterprise Linux 8 and its extended life cycle variants that fix these vulnerabilities. Users should apply the security update RHSA-2026:1224 promptly to remediate the issues. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigations are indicated by the vendor advisory.
Red Hat Security Advisory: python3.11-urllib3 security update
Description
This advisory addresses multiple security vulnerabilities in the python3. 11-urllib3 package for Red Hat Enterprise Linux 8. The issues include unbounded decompression chains leading to resource exhaustion, improper handling of highly compressed data in the streaming API, and a decompression-bomb safeguard bypass when following HTTP redirects. These vulnerabilities could potentially be exploited to cause denial of service conditions. Red Hat has released updated packages to fix these issues. The update is rated as having an Important security impact by Red Hat Product Security.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The python3.11-urllib3 package in Red Hat Enterprise Linux 8 contains three related vulnerabilities: CVE-2025-66418 involves an unbounded decompression chain that can lead to resource exhaustion; CVE-2025-66471 concerns improper handling of highly compressed data in the urllib3 streaming API; and CVE-2026-21441 allows bypassing the decompression-bomb safeguard when following HTTP redirects in the streaming API. These flaws relate to how urllib3 processes compressed HTTP content, potentially enabling denial of service via resource exhaustion. Red Hat has issued security updates (RHSA-2026:1224) that address these vulnerabilities across multiple architectures and extended life cycle versions of RHEL 8.
Potential Impact
The vulnerabilities can lead to resource exhaustion through unbounded decompression chains or bypassing decompression safeguards, which may cause denial of service conditions in applications using the affected urllib3 streaming API. No known exploits are reported in the wild. The impact is rated as Important by Red Hat, indicating a high severity but not critical.
Mitigation Recommendations
Red Hat has released updated python3.11-urllib3 packages for Red Hat Enterprise Linux 8 and its extended life cycle variants that fix these vulnerabilities. Users should apply the security update RHSA-2026:1224 promptly to remediate the issues. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigations are indicated by the vendor 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-2026:1224
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-66471","CVE-2026-21441"]
- Cvss Version
- null
Threat ID: 6a16096de29bf47b50634103
Added to database: 5/26/2026, 8:58:21 PM
Last enriched: 5/27/2026, 1:19:28 AM
Last updated: 5/27/2026, 4:48:43 AM
Views: 2
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