CVE-2026-65905 — tomcat
CRITICALCVE-2026-65905 is a critical-severity (CVSS 9.8) CWE-294 vulnerability in org.apache.tomcat:tomcat. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.
Apache Tomcat: Limited replay attack possible with DIGEST authentication
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-65905.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-65905 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,993 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core+7 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | ≥ 11.0.0-M1&&< 11.0.25 | 11.0.25org.apache.tomcat:tomcat:11.0.25 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 10.1.0-M1&&< 10.1.58 | 10.1.58org.apache.tomcat:tomcat:10.1.58 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 9.0.0.M1&&< 9.0.121 | 9.0.121org.apache.tomcat:tomcat:9.0.121 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 8.5.0 | No fix |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 7.0.30 | No fix |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 11.0.0-M1&&< 11.0.25 | 11.0.25org.apache.tomcat.embed:tomcat-embed-core:11.0.25 |
Affected Products
tomcatapacheDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 11.0.25 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-65905 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Moderate impact flaw in Apache Tomcat's DIGEST authenticator allows a limited authentication bypass through a replay attack. While the attack complexity is high, a remote attacker could potentially replay a single authenticated request if the nonceCount is at the upper boundary of the replay window, leading to…
To mitigate this issue, disable DIGEST authentication in Apache Tomcat if it is not a required authentication mechanism for your deployment. Refer to the Apache Tomcat documentation for guidance on configuring authentication methods. Disabling DIGEST authentication will affect services that depend on it. A restart of the Tomcat service is necessary for the configuration changes to be applied.Source: Red Hat security advisory for CVE-2026-65905 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat JBoss Web Server 6.2.5 | tomcat | RHSA-2026:73982 |
| Red Hat JBoss Web Server 6.2 on RHEL 10 | jws6-tomcat-0:10.1.49-16.redhat_00016.1.el10jws | RHSA-2026:73981 |
| Red Hat JBoss Web Server 7.0.2 | tomcat | RHSA-2026:76956 |
| Red Hat JBoss Web Server 7.0 on RHEL 10 | jws7-tomcat-0:11.0.21-7.redhat_00006.1.el10jws | RHSA-2026:76952 |
| Red Hat Hardened Images | tomcat11-main-11.0.25-0.1.hum1 | RHSA-2026:56039 |
| Red Hat Hardened Images | tomcat10-main-10.1.59-0.1.hum1 | RHSA-2026:63137 |
Frequently Asked Questions
Is CVE-2026-65905 in your dependencies?
Find it across Maven, including transitive dependencies.