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Response snapshot Oct 27, 2026, 03:56 UTC

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VulnerabilityCVE-2026-53434

Apache Tomcat util accepted misconfigured CRLs

Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring Certificate Revocation List (CRLs) for a FFM based connector. If an FFM connector was configured with invalid CRLs, the invalid CRLs were ignored meaning invalid certificates could be accepted.

At a glance

Exploited
Not known
Severity
9.1 Critical (CVSS 3.1)
Chance of exploitation
0.6% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: org.apache.tomcat:tomcat-util: 11.0.23; org.apache.tomcat:tomcat-util: 10.1.56; org.apache.tomcat:tomcat-util: 9.0.119. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-4x29-79gh-6v8q (opens a new tab)

What happened

Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring Certificate Revocation List (CRLs) for a FFM based connector. If an FFM connector was configured with invalid CRLs, the invalid CRLs were ignored meaning invalid certificates could be accepted.

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.

Affected package ranges reported by GitHub: org.apache.tomcat:tomcat-util: >= 11.0.0-M1, <= 11.0.22 org.apache.tomcat:tomcat-util: >= 10.1.0-M7, <= 10.1.55 org.apache.tomcat:tomcat-util: >= 9.0.83, <= 9.0.118

Scores and how they were measured

CVSS base severity

9.1

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.6%

Scored Percentile 47.7%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-4x29-79gh-6v8q (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-4x29-79gh-6v8q, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-53434, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 23). Apache Tomcat util accepted misconfigured CRLs (CVE-2026-53434). https://kevwire.com/record/CVE-2026-53434

MLA

"Apache Tomcat util accepted misconfigured CRLs (CVE-2026-53434)." KEVWire, 23 Oct. 2026, kevwire.com/record/CVE-2026-53434.

Chicago

KEVWire. "Apache Tomcat util accepted misconfigured CRLs (CVE-2026-53434)." Last modified October 23, 2026. https://kevwire.com/record/CVE-2026-53434.

Evidence summary (plain text)

Apache Tomcat util accepted misconfigured CRLs (Jun 29, 2026).
Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring Certificate Revocation List (CRLs) for a FFM based connector. If an FFM connector was configured with invalid CRLs, the invalid CRLs were ignored meaning invalid certificates could be accepted.

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.
CVSS 9.1 (version 3.1; evidence as of Oct 23, 2026; https://github.com/advisories/GHSA-4x29-79gh-6v8q).
EPSS 0.6% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-53434&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-4x29-79gh-6v8q: https://github.com/advisories/GHSA-4x29-79gh-6v8q
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-53434&date=2026-10-26
Record ID: CVE-2026-53434.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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