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🛡️ CVE-2026-34487 — tomcat

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-532 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Apache Tomcat: Cloud membership for clustering component exposed the Kubernetes bearer token

Insertion of Sensitive Information into Log File vulnerability in the cloud membership for clustering component of Apache Tomcat exposed the Kubernetes bearer token.

This issue affects Apache Tomcat: from 11.0.0 through 11.0.20, from 10.1.0 through 10.1.53, from 9.0.13 through 9.0.116.

Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117, which fix the issue.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: None.
  • Availability impact: None.

Weakness class

CVE-2026-34487 is classified as CWE-532: Insertion of Sensitive Information into Log File. Sensitive values are written to logs, which are typically kept longer and read more widely than the data warrants.

Affected software

CVE-2026-34487 is recorded against 4 packages.

  • org.apache.tomcat.embed:tomcat-embed-core (from 11.0.0-M1 up to 11.0.21)
  • org.apache.tomcat:tomcat (from 11.0.0-M1 up to 11.0.21)
  • org.apache.tomcat:tomcat-tribes (from 11.0.0-M1 up to 11.0.21)
  • tomcat

Timeline and source

Published on 9 April 2026 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Package)
lists.apache.org (Web)
tomcat.apache.org (Web)
tomcat.apache.org (Web)
tomcat.apache.org (Web)
www.openwall.com (Web)

Other advisories for this package

org.apache.tomcat:tomcat has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-532: Insertion of Sensitive Information into Log File) in other software:

CVE-2026-34487 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE CWE-532
Public Exploit ✅ No
Source OSV
Published 2026-04-09
Updated 2026-08-20
Modified 2026-08-12
Fix URL N/A

Affected Packages

Software From version Fixed in
org.apache.tomcat:tomcat 11.0.0-M1 11.0.21
org.apache.tomcat:tomcat-tribes 11.0.0-M1 11.0.21
org.apache.tomcat.embed:tomcat-embed-core 11.0.0-M1 11.0.21
tomcat — —

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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