Advisory severityHigh7.4Apache Software Foundation

High [CVE-2026-86247] Race condition within a thread vulnerability in Apache Tomcat Native allowed client certificate verification requirements to be down-graded for some configurations

This high-severity Apache Software Foundation advisory covers CVE-2026-86247 affecting Apache Tomcat Native.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-86247 Source published Sep 23, 2026Source updated Sep 23, 2026

VulniPulse record published Sep 23, 2026Record updated Sep 23, 2026

CVE-2026-86247

Affected products & platforms

Apache Software FoundationTomcat

Open source advisory

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Summary

Race condition within a thread vulnerability in Apache Tomcat Native allowed client certificate verification requirements to be down-graded for some configurations.

This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Unsupported versions may also be affected.

Users are recommended to upgrade to version 2.0.16 or 1.3.9, which fixes the issue.

Affected versions

2.0.0 through 2.0.15
1.3.0 through 1.3.8.
through 1.3.8

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Fixed versions

2.0.16
1.3.9

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation

Users are recommended to upgrade to version 2.0.16 or 1.3.9, which fixes the issue.

Official advisory · high-confidence parse· fetched 13 days ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Official vendor advisoryofficial
Official advisory page fetched and parsed; accepted detail fields are attributed to this page.
Apache Software Foundation
CVE.org CNA recordCVE.org
Independent CNA record used for near-real-time discovery and missed-CVE reconciliation. Discovered from the machine-readable feed https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/delta.json; this link opens the CVE.org record for CVE-2026-86247 instead of the raw feed document.
CVE Program

Cross-references

Validate CVE metadata against the authoritative registries.

CVE-2026-86247NVD CVE.org MITRE

Official resources

Apache Tomcat security bulletins (per major version) (target: 2.0.16 / 1.3.9)
Official documentation
This advisory names 2.0.16 / 1.3.9 as the first fixed releases — official upgrade documentation for Apache Tomcat security bulletins (per major version).
ASF Security — reporting & CVE process
Official documentation
The Apache Software Foundation's official security page: how ASF CVEs are published and where each project's advisories live.
Apache project downloads (fixed releases)
Official documentation
Official ASF download tree — fetch the fixed release named in this advisory from the project's directory.

Discussion(0)

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