Race Condition Vulnerability in Apache Tomcat Native
CVE-2026-86247

7.4HIGH

Key Information:

Vendor

Apache
Status
Apache Tomcat Native
Vendor
CVE Published:
23 September 2026

What is CVE-2026-86247?

The Apache Tomcat Native server has a race condition vulnerability that affects client certificate verification, allowing configuration downgrades in specific setups. This flaw compromises the integrity of secure connections. Users are advised to update to versions 2.0.16 or 1.3.9 to mitigate this risk, as unsupported versions may also be susceptible.

Affected Version(s)

Apache Tomcat Native 2.0.0 <= 2.0.15

Apache Tomcat Native 1.3.0 <= 1.3.8

References

https://lists.apache.org/thread/obsson6zhvfg0wsp2bx602l61...
vendor-advisory

CVSS V3.1

Score:
7.4
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.