Improper Validation of Specified Quantity in Input The advisory has been revoked - it doesn't affect any version of package zlib (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-UBUNTU2510-ZLIB-15354590
- published25 Jun 2026
- disclosed18 Feb 2026
Introduced: 18 Feb 2026
CVE-2026-27171 (opens in a new tab)Amendment
The Ubuntu security team deemed this advisory irrelevant for Ubuntu:25.10.
NVD Description
Note: Versions mentioned in the description apply only to the upstream zlib package and not the zlib package as distributed by Ubuntu.
zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2026-27171
- https://7asecurity.com/blog/2026/02/zlib-7asecurity-audit/
- https://github.com/madler/zlib/releases/tag/v1.3.2
- https://ostif.org/zlib-audit-complete/
- https://github.com/madler/zlib/issues/904
- https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf