CVE-2025-31650 Apache Tomcat: DoS via malformed HTTP/2 PRIORITY_UPDATE frame

What is CVE-2025-31650?

CVE-2025-31650 is a high-severity denial of service vulnerability in Apache Tomcat, published on 28 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Improper Input Validation vulnerability in Apache Tomcat. Incorrect error handling for some invalid HTTP priority headers resulted in incomplete clean-up of the failed request which created a memory leak. A large number of such requests could trigger an OutOfMemoryException resulting in a denial of service.

This issue affects Apache Tomcat: from 9.0.76 through 9.0.102, from 10.1.10 through 10.1.39, from 11.0.0-M2 through 11.0.5. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.90 though 8.5.100.

Users are recommended to upgrade to version 9.0.104, 10.1.40 or 11.0.6 which fix the issue.

Weakness: CWE-459

Which versions are affected by CVE-2025-31650?

17 open source packages ship an affected version, including org.apache.tomcat.embed:tomcat-embed-core, tomcat and org.apache.tomcat:tomcat-coyote. It affects 1 product.

Products include Apache Tomcat.

How do I fix CVE-2025-31650?

Upgrade org.apache.tomcat.embed:tomcat-embed-core to a fixed version for your release line: 10.1.40, 11.0.6 or 9.0.104.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-31650 being exploited?

There is no known exploitation of CVE-2025-31650 in the wild and no public exploit code.

Public exploit code: 1 Exploit-DB entry and 6 proofs of concept on GitHub.

Other vulnerabilities in Apache Tomcat

• CVE-2025-24813 Apache Tomcat Path Equivalence Exploited Critical 10.0
• CVE-2016-8735 Apache Tomcat Remote Code Execution Exploited Critical 9.8
• CVE-2017-12617 Apache Tomcat Remote Code Execution Exploited High 8.1
• CVE-2017-12615 Apache Tomcat on Windows Remote Code Execution Exploited High 8.1
• CVE-2026-34486 Apache Tomcat Missing Encryption of Sensitive Data Exploited High 7.5

All Apache Tomcat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-tomcat-2025-31650, CLEANSTART-2026-SR71382, DEBIAN-CVE-2025-31650, GHSA-3p2h-wqq4-wf4h, MINI-9pcj-gjqc-xv52, MINI-cccq-jpcw-6w4f and 3 more.