Vulnerability/
https://seclists.org/oss-sec/2026/q3/905

https://seclists.org/oss-sec/2026/q3/905: CVE-2026-78437: Apache Tomcat: HTTP/2 DoS via malformed quest

Q: Is Apache Tomcat 8.5 affected?

Apache Tomcat 8.5 through 8.5.100 is listed as unaffected.

Q: Which supported release lines are listed as affected?

Affected versions are Tomcat 11.0.19 through 11.0.25, 10.1.53 through 10.1.59, and 9.0.116 through 9.0.121. The provided data does not state the status of versions outside these ranges.

Published Sep 23, 2026

Updated

Affected Software

1 affected component

Apache Tomcat>=11.0.19<=11.0.25, >=10.1.53<=10.1.59, >=9.0.116<=9.0.121

Frequently Asked Questions

Is Apache Tomcat 8.5 affected?

Apache Tomcat 8.5 through 8.5.100 is listed as unaffected.

Which supported release lines are listed as affected?

Affected versions are Tomcat 11.0.19 through 11.0.25, 10.1.53 through 10.1.59, and 9.0.116 through 9.0.121. The provided data does not state the status of versions outside these ranges.

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