Red Hat Security Advisory: python3.12-urllib3 security update
Multiple security vulnerabilities have been identified in the python3. 12-urllib3 package used in Red Hat Enterprise Linux 8. These include an unbounded decompression chain leading to resource exhaustion (CVE-2025-66418), improper handling of highly compressed data in the streaming API (CVE-2025-66471), and a decompression-bomb safeguard bypass when following HTTP redirects in the streaming API (CVE-2026-21441). Red Hat has released an important security update addressing these issues. The vulnerabilities relate to resource exhaustion and improper data handling in urllib3's decompression mechanisms.
AI Analysis
Technical Summary
The python3.12-urllib3 package in Red Hat Enterprise Linux 8 contains multiple vulnerabilities involving decompression handling. CVE-2025-66418 describes an unbounded decompression chain that can lead to resource exhaustion. CVE-2025-66471 involves improper handling of highly compressed data in the urllib3 streaming API. CVE-2026-21441 details a bypass of the decompression-bomb safeguard when following HTTP redirects using the streaming API. These issues could allow an attacker to cause resource exhaustion or bypass safeguards designed to prevent decompression bombs. Red Hat has issued an important security advisory (RHSA-2026:1226) with updated packages to remediate these vulnerabilities.
Potential Impact
The vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data. This could degrade system performance or availability. The decompression-bomb safeguard bypass could allow attackers to circumvent protections against maliciously crafted compressed data. No known exploits in the wild have been reported. The impact is rated as important by Red Hat, indicating a high severity but not critical.
Mitigation Recommendations
Red Hat has released updated python3.12-urllib3 packages that address these vulnerabilities. Users of Red Hat Enterprise Linux 8 should apply the security update described in advisory RHSA-2026:1226 as soon as possible. Detailed update instructions are available at https://access.redhat.com/articles/11258. Since this is not a cloud service, remediation requires applying the vendor-provided package updates. No additional mitigations are specified by Red Hat beyond applying the update.
Red Hat Security Advisory: python3.12-urllib3 security update
Description
Multiple security vulnerabilities have been identified in the python3. 12-urllib3 package used in Red Hat Enterprise Linux 8. These include an unbounded decompression chain leading to resource exhaustion (CVE-2025-66418), improper handling of highly compressed data in the streaming API (CVE-2025-66471), and a decompression-bomb safeguard bypass when following HTTP redirects in the streaming API (CVE-2026-21441). Red Hat has released an important security update addressing these issues. The vulnerabilities relate to resource exhaustion and improper data handling in urllib3's decompression mechanisms.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The python3.12-urllib3 package in Red Hat Enterprise Linux 8 contains multiple vulnerabilities involving decompression handling. CVE-2025-66418 describes an unbounded decompression chain that can lead to resource exhaustion. CVE-2025-66471 involves improper handling of highly compressed data in the urllib3 streaming API. CVE-2026-21441 details a bypass of the decompression-bomb safeguard when following HTTP redirects using the streaming API. These issues could allow an attacker to cause resource exhaustion or bypass safeguards designed to prevent decompression bombs. Red Hat has issued an important security advisory (RHSA-2026:1226) with updated packages to remediate these vulnerabilities.
Potential Impact
The vulnerabilities can lead to resource exhaustion on affected systems due to unbounded decompression chains and improper handling of compressed data. This could degrade system performance or availability. The decompression-bomb safeguard bypass could allow attackers to circumvent protections against maliciously crafted compressed data. No known exploits in the wild have been reported. The impact is rated as important by Red Hat, indicating a high severity but not critical.
Mitigation Recommendations
Red Hat has released updated python3.12-urllib3 packages that address these vulnerabilities. Users of Red Hat Enterprise Linux 8 should apply the security update described in advisory RHSA-2026:1226 as soon as possible. Detailed update instructions are available at https://access.redhat.com/articles/11258. Since this is not a cloud service, remediation requires applying the vendor-provided package updates. No additional mitigations are specified by Red Hat beyond applying the update.
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"]
- Cvss Version
- null
Threat ID: 6a16096de29bf47b506340fb
Added to database: 5/26/2026, 8:58:21 PM
Last enriched: 5/27/2026, 1:19:34 AM
Last updated: 5/27/2026, 5:02:41 AM
Views: 2
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