CVE-2026-53434: Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CRLs for a FFM bas

Q: How do I fix CVE-2026-53434?

tomcat: upgrade to 9.0.119, 10.1.56, 11.0.23. Exact commands for each OS are on this page.

Q: Is CVE-2026-53434 being exploited?

CVE-2026-53434 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-53434 affect?

CVE-2026-53434 affects tomcat. Severity is critical (CVSS 9.1). Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CRLs for a FFM based connector. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, from 9.0.83 throu

Q: How urgent is CVE-2026-53434?

Priority 57/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

This month

CRITICAL 9.1REMOTEWATCHLISTUPGRADE

CVE-2026-53434 is a critical-severity flaw (CVSS 9.1) affecting tomcat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CRLs for a FFM based connector. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, from 9.0.83 through 9.0.118. Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fixes the issue.

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-390
Published	2026-06-29
Last modified	2026-10-25

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

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-29 21:16 UTCPublished CVE record published
2026-10-25 21:10 UTCUpdated Record last modified

apache tomcat UPGRADE

Affected: >= 9.0.83 and < 9.0.119 · >= 10.1.0 and < 10.1.56 · >= 11.0.0 and < 11.0.23

Fixed in: 9.0.119, 10.1.56, 11.0.23

Safe to downgrade to: a release before 9.0.83

1. Check installed version

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

2. UPGRADE to 9.0.119 (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 9.0.83 (Debian / Ubuntu)

apt-cache madison tomcat sudo apt install tomcat=<VERSION_BEFORE_9.0.83> 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_9.0.83> 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.

Exact fixes by distribution

Maven · org.apache.tomcat:tomcat-util · FIXED · 11.0.23 · vulnerable: >= 11.0.0-M1, <= 11.0.22 · source

Set org.apache.tomcat:tomcat-util to 11.0.23 or later in pom.xml or build.gradle, then rebuild and redeploy.

Fedora 46 · mingw-qt5-qtwebkit · FIXED · 5.212.0-0.46.alpha4.fc46 · FEDORA-2026-46ae541c22 · source

sudo dnf upgrade --advisory=FEDORA-2026-46ae541c22

Fedora ELN · kdominate · FIXED · 26.08.2-2.eln159 · FEDORA-2026-b1d98239fd · source

sudo dnf upgrade --advisory=FEDORA-2026-b1d98239fd

Debian 12 · tomcat10 · NO FIX YET

Debian 13 · tomcat10 · NO FIX YET

Debian 13 · tomcat11 · NO FIX YET

Debian 12 · tomcat9 · FIXED · 9.0.70-2

sudo apt update && sudo apt install --only-upgrade tomcat9 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tomcat9)" ge "9.0.70-2" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · tomcat9 · FIXED · tomcat9-9.0.120-1.el10_2

sudo dnf upgrade --advisory=RHSA-2026:68651 rpm -q tomcat9

RHEL 10.0 Extended Update Support · tomcat9 · FIXED · tomcat9-9.0.120-1.el10_0

sudo dnf upgrade --advisory=RHSA-2026:67163 rpm -q tomcat9

RHEL 8 · tomcat · FIXED · tomcat-9.0.120-1.el8_10

sudo dnf upgrade --advisory=RHSA-2026:68677 rpm -q tomcat

RHEL 8.8 Telecommunications Update Service · tomcat · FIXED · tomcat-9.0.120-1.el8_8

sudo dnf upgrade --advisory=RHSA-2026:68680 rpm -q tomcat

RHEL 8.8 Update Services for SAP Solutions · tomcat · FIXED · tomcat-9.0.120-1.el8_8

sudo dnf upgrade --advisory=RHSA-2026:68680 rpm -q tomcat

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-1946 · source

sudo dnf update --advisory=ALAS2023-2026-1946

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-2026-53434?

tomcat: upgrade to 9.0.119, 10.1.56, 11.0.23. Exact commands for each OS are on this page.

Is CVE-2026-53434 being exploited?

CVE-2026-53434 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-2026-53434 affect?

CVE-2026-53434 affects tomcat. Severity is critical (CVSS 9.1). Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CRLs for a FFM based connector. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, from 9.0.83 throu

How urgent is CVE-2026-53434?

Priority 57/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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