What is CVE-2026-86246?

CVE-2026-86246 is a critical-severity vulnerability in Apache Tomcat Native, classified under Initialization of a Resource with an Insecure Default. CVSS score: 9.1/10. Published 2026-09-23.

How severe is CVE-2026-86246?

Critical severity. CVSS v3 base score is 9.1 out of 10.

RCE in Apache Tomcat Native

CVE-2026-86246

Initialization of a resource with an insecure default vulnerability in Apache Tomcat Native enabled insecure options by default including ALLOW_CLIENT_RENEGOTIATION, NO_EXTENDED_MASTER_SECRET, IGNORE_UNEXPECTED_EOF and ALLOW_NO_DHE_KEX. 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 2.0.16 or 1.3.9, which fix the issue.

Published 2026-09-23 · last modified 2026-10-06.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (28.5th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.000

Affected products

Weakness classification (CWE)

CWE-1188 — Initialization of a Resource with an Insecure Default

References

lists.apache.org/thread/dgyvfwb24nbk45ptvlhdyhdhl5o7k5ol (vendor-advisory, Mailing List, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-86246?: CVE-2026-86246 is a critical-severity vulnerability in Apache Tomcat Native, classified under Initialization of a Resource with an Insecure Default. CVSS score: 9.1/10. Published 2026-09-23.
How severe is CVE-2026-86246?: Critical severity. CVSS v3 base score is 9.1 out of 10.