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Apache Tomcat's DIGEST authenticator has an Authentication Bypass by Capture-replay vulnerability

Critical severity GitHub Reviewed Published Aug 26, 2026 to the GitHub Advisory Database • Updated Sep 2, 2026

Package

maven org.apache.tomcat.embed:tomcat-embed-core (Maven)

Affected versions

>= 11.0.0-M1, < 11.0.25
>= 10.1.0-M1, < 10.1.58
>= 9.0.0.M1, < 9.0.121
>= 8.5.0, <= 8.5.100
>= 7.0.30, <= 7.0.109

Patched versions

11.0.25
10.1.58
9.0.121
maven org.apache.tomcat:tomcat (Maven)
>= 11.0.0-M1, < 11.0.25
>= 10.1.0-M1, < 10.1.58
>= 9.0.0.M1, < 9.0.121
>= 8.5.0, <= 8.5.100
>= 7.0.30, <= 7.0.109
11.0.25
10.1.58
9.0.121
maven org.apache.tomcat:tomcat-catalina (Maven)
>= 11.0.0-M1, < 11.0.25
>= 10.1.0-M1, < 10.1.58
>= 9.0.0.M1, < 9.0.121
>= 8.5.0, <= 8.5.100
>= 7.0.30, <= 7.0.109
11.0.25
10.1.58
9.0.121

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.

References

Published by the National Vulnerability Database Aug 25, 2026
Published to the GitHub Advisory Database Aug 26, 2026
Reviewed Sep 2, 2026
Last updated Sep 2, 2026

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(53rd percentile)

Weaknesses

Authentication Bypass by Capture-replay

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). Learn more on MITRE.

CVE ID

CVE-2026-65905

GHSA ID

GHSA-9xv2-5v5q-p794

Source code

Credits

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