CVE-2026-68763: Apache Tomcat: DoS via allocation leak in HTTP/2 backlog tracking when a stream is reset

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-25 · updated 2026-08-27
Weakness: CWE-400

Description

Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2 backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

Affected products

Apache Tomcat: from 8.5.59 before 9.0.121; from 10.1.0 before 10.1.58; from 11.0.0 before 11.0.25 — fixed in 10.1.58, 11.0.25, 9.0.121

How to fix

Upgrade to a fixed version: Apache Tomcat 10.1.58, 11.0.25, 9.0.121. Check the vendor advisory for mitigations.

References

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