CVE-2026-86247: Apache Tomcat Native · Race Condition Within a Thread
Affects Apache Tomcat NativeSource CVE Database V5
Not known to be exploited · CVSS 7.4 High · fixed in 1.3.9 : patch Apache Tomcat Native soon.
Data as of 6 Nov 2026, 23:24 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.3.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache Tomcat Native | Affected
| Fixed in– |
AI-suggested
Users should upgrade affected Apache Tomcat Native versions to 1.3.9 or 2.0.16 or later, where this race condition vulnerability is fixed. No other mitigations are indicated by the vendor advisory.
Description
A race condition vulnerability in Apache Tomcat Native allows client certificate verification requirements to be downgraded under certain configurations. This affects versions 1.3.0 through 1.3.8 and 2.0.0 through 2.0.15. The issue is fixed in versions 1.3.9 and 2.0.16. The vulnerability has a high severity rating with a CVSS score of 7.4.