9.8Critical

Apache Tomcat

CVE-2026-65905

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.

What this means for your business

  • It affects Apache Tomcat. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.8% chance of attack attempts being seen in the next 30 days, ranking above 54% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Apache Tomcat, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Fastnexa security experts

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Scoring

CVSS
9.8 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-294
Assigned by
security@apache.org

Dates

Published
2026-08-25
Last modified
2026-08-27
Sources
NVD

Affected products

  • Apache Tomcat7.0.30 - 7.0.109, 8.5.0 - 9.0.121, 10.1.0 - 10.1.58, 11.0.0 - 11.0.25

As listed in the NVD configuration data. Not a statement about your estate.

References