CVE-2026-86246 (CVSS 9.1)

Description

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.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0036

Probability of exploitation

0.29%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-1188 CWE-1188

References

Other References

https://lists.apache.org/thread/dgyvfwb24nbk45ptvlhdyhdhl5o7k5ol http://www.openwall.com/lists/oss-security/2026/09/23/32

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-86246? +

CVE-2026-86246 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0036, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-86246? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-86246