CVE-2026-65905 Apache Tomcat: Limited replay attack possible with DIGEST authentication

What is CVE-2026-65905?

CVE-2026-65905 is a critical authentication bypass 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

Authentication Bypass by Capture-replay vulnerability in Apache Tomcat's DIGEST authenticator. If, before windowSize requests have been made, a client makes a DIGEST authenticated request with a nonceCount on the upper boundary of the replay window then that request is replayable once only while the associated nonceCount remains within the replay window.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120.

The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.30 through 7.0.109. 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-294

Which versions are affected by CVE-2026-65905?

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

Products include Apache Tomcat.

How do I fix CVE-2026-65905?

Upgrade org.apache.tomcat.embed:tomcat-embed-core to a fixed version for your release line: 10.1.58, 11.0.25 or 9.0.121.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-65905 being exploited?

There is no known exploitation of CVE-2026-65905 in the wild and no public exploit code.

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-2026-65905, DEBIAN-CVE-2026-65905, ECHO-566e-60a7-a73e, GHSA-9xv2-5v5q-p794, MINI-4hpm-m9hw-xqhq, MINI-69hp-3wj8-9p6c and 5 more.