Improper Validation of Unsafe Equivalence in Input Affecting org.apache.tomcat:tomcat-catalina package, versions [9.0.115, 9.0.121)[10.1.53, 10.1.59)[11.0.20, 11.0.25)
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.
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Test your applications- Snyk IDSNYK-JAVA-ORGAPACHETOMCAT-19345313
- published27 Aug 2026
- disclosed26 Aug 2026
- creditParag Ambildhuke
Introduced: 26 Aug 2026
NewCVE-2026-65637 (opens in a new tab)How to fix?
Upgrade org.apache.tomcat:tomcat-catalina to version 9.0.121, 10.1.59, 11.0.25 or higher.
Overview
org.apache.tomcat:tomcat-catalina is a Tomcat Servlet Engine Core Classes and Standard implementations.
Affected versions of this package are vulnerable to Improper Validation of Unsafe Equivalence in Input in the HTTP/2 request handling. An attacker can bypass strict SNI validation by crafting requests that exploit incomplete input validation.
Note: This issue was fixed in Apache Tomcat 10.1.58 but the release vote for the 10.1.58 release candidate did not pass. Therefore, although users must download 10.1.59 to obtain a version that includes a fix for this issue, version 10.1.58 is not included in the list of affected versions.