CVE-2026-53434Network attack vector

Authentication bypass via ignored CRL loading errors

Published Jun 29, 2026 · Updated Jun 29, 2026

Improper CRL error handling in affected Apache Tomcat releases allows remote attackers to authenticate with invalid client certificates. OpenSSLContext logs and ignores failures from CRL file or directory loading instead of aborting FFM connector initialization. Exposure requires an FFM-based TLS connector configured for client authentication and CRL checking; revoked or otherwise invalid certificates can pass authentication.

CVSS severity9.1
Critical
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper CRL error handling in affected Apache Tomcat releases allows remote attackers to authenticate with invalid client certificates. OpenSSLContext logs and ignores failures from CRL file or directory loading instead of aborting FFM connector initialization. Exposure requires an FFM-based TLS connector configured for client authentication and CRL checking; revoked or otherwise invalid certificates can pass authentication.

The record

CVE
CVE-2026-53434
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
The Apache Software Foundation
Product
Apache Tomcat
Classifications
CWE-390, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.1.0-M7 <=10.1.55
  2. Affected versionversion=11.0.0-M1 <=11.0.22
  3. Affected versionversion=9.0.83 <=9.0.118

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Tomcatversion=10.1.0-M7 <=10.1.55; version=11.0.0-M1 <=11.0.22; version=9.0.83 <=9.0.118

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-390Detection of Error Condition Without Action
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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