CVE-2026-68763 Apache Tomcat: DoS via allocation leak in HTTP/2 backlog tracking when a stream is reset
Attackers can cause denial of service in Apache Tomcat by triggering an allocation leak in HTTP/2 backlog tracking when resetting streams.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68763?
CVE-2026-68763 is a high-severity denial of service vulnerability in Apache Tomcat, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-68763?
1 open source package ship an affected version, including tomcat. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tomcat Bitnami | From 8.5.59 | 9.0.121, 10.1.58, 11.0.25 |
Products include Apache Tomcat.
How do I fix CVE-2026-68763?
Upgrade tomcat to a fixed version for your release line: 9.0.121, 10.1.58 or 11.0.25.
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-2026-68763 being exploited?
There is no known exploitation of CVE-2026-68763 in the wild and no public exploit code.
Other vulnerabilities in Apache Tomcat
Sources
Also known as BIT-tomcat-2026-68763, DEBIAN-CVE-2026-68763, GHSA-82jr-6mfr-9vq5, MINI-3858-953g-mvh3, MINI-4gqh-h44w-h458, MINI-fj79-jcxh-vq4p and 1 more.