CVE-2026-65905: Authentication Bypass by Capture-replay vulnerability in Apache Tomcat's DIGEST authenticator

This month

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-65905 is a critical-severity flaw (CVSS 9.8) affecting tomcat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 thr

Why this priority

Critical severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-294
Published	2026-08-25
Last modified	2026-08-27

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-08-27 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-25 22:17 UTCPublished CVE record published
2026-08-27 15:17 UTCUpdated Record last modified

apache tomcat UPGRADE

Affected: >= 7.0.30 and <= 7.0.109 · >= 8.5.0 and < 9.0.121 · >= 10.1.0 and < 10.1.58 · >= 11.0.0 and < 11.0.25

Fixed in: 9.0.121, 10.1.58, 11.0.25

Safe to downgrade to: a release before 7.0.30

1. Check installed version

apt-cache policy tomcat || rpm -q tomcat || tomcat --version

2. UPGRADE to 9.0.121 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tomcat

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tomcat

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.0.30 (Debian / Ubuntu)

apt-cache madison tomcat sudo apt install tomcat=<VERSION_BEFORE_7.0.30> sudo apt-mark hold tomcat

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list tomcat sudo dnf downgrade tomcat-<VERSION_BEFORE_7.0.30> sudo dnf versionlock add tomcat

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

Amazon Linux 2023 ALAS: ALAS2023-2026-3151 (important): tomcat11 2026-10-12

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-65905?

tomcat: upgrade to 9.0.121, 10.1.58, 11.0.25. Exact commands for each OS are on this page.

Is CVE-2026-65905 being exploited?

CVE-2026-65905 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-65905 affect?

CVE-2026-65905 affects tomcat. Severity is critical (CVSS 9.8). 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 rep

How urgent is CVE-2026-65905?

Priority 56/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Tomcat vulnerabilities

Related CVEs

CVE-2026-34486 HIGH 7.5 EXPLOITED DOWNGRADE DOWNGRADE Apache Tomcat Missing Encryption of Sensitive Data Vulnerability
CVE-2026-29146 HIGH 7.5 UPGRADE Padding Oracle vulnerability in Apache Tomcat's EncryptInterceptor with default configuration. This issue aff
CVE-2026-25854 MEDIUM 6.1 UPGRADE Occasional URL redirection to untrusted Site ('Open Redirect') vulnerability in Apache Tomcat via the LoadBala
CVE-2026-29145 CRITICAL 9.1 UPGRADE UPGRADE CLIENT_CERT authentication does not fail as expected for some scenarios when soft fail is disabled vulnerabili
CVE-2026-24880 HIGH 7.5 UPGRADE Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomca

References

← Back to latest CVEs