Vulnerability in Apache Tomcat Native

CVE-2026-86243

Buffer over-read vulnerability in Apache Tomcat Native during the TLS handshake permits a malicious user to trigger a DoS via a JVM crash. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Earlier, unsupported versions may also be affected. Users are recommended to upgrade to version 1.3.9 or 2.0.16, which fix the issue.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86243: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86243?
CVE-2026-86243 is a high-severity vulnerability in Apache Tomcat Native, classified under Buffer Over-read. CVSS score: 7.5/10. Published 2026-09-23.
How severe is CVE-2026-86243?
High severity. CVSS v3 base score is 7.5 out of 10.