CVE-2026-55276

Misleading security logs via omitted authorization constraints

Published Jun 29, 2026 · Updated Jun 29, 2026

Incorrect control flow in Apache Tomcat causes logged effective web.xml output to omit authorization data from affected releases. WebXml.toXml() emitted auth-constraint only for explicit role entries, skipping special-role flags and explicitly empty constraints. Affected branches span 8.5.0 through 8.5.100, 9.0.0.M1 through 9.0.118, 10.1.0-M1 through 10.1.55, and 11.0.0-M1 through 11.0.22; exposure requires non-default effective-descriptor logging, and the resulting audit log misrepresents the enforced policy.

CVSS severity9.1
Critical
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect control flow in Apache Tomcat causes logged effective web.xml output to omit authorization data from affected releases. WebXml.toXml() emitted auth-constraint only for explicit role entries, skipping special-role flags and explicitly empty constraints. Affected branches span 8.5.0 through 8.5.100, 9.0.0.M1 through 9.0.118, 10.1.0-M1 through 10.1.55, and 11.0.0-M1 through 11.0.22; exposure requires non-default effective-descriptor logging, and the resulting audit log misrepresents the enforced policy.

The record

CVE
CVE-2026-55276
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
The Apache Software Foundation
Product
Apache Tomcat
Classifications
CWE-670
Attack vector
Unavailable
Privileges
Unavailable

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-M1 <=10.1.55
  2. Affected versionversion=11.0.0-M1 <=11.0.22
  3. Affected versionversion=8.5.0 <=8.5.100
  4. Affected versionversion=9.0.0.M1 <=9.0.118

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Apache Software Foundation · Apache Tomcatversion=10.1.0-M1 <=10.1.55; version=11.0.0-M1 <=11.0.22; version=8.5.0 <=8.5.100; version=9.0.0.M1 <=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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

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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