---
title: "CVE-2026-86246: Apache Tomcat Native - Insecure Default Configuration"
description: "Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 contain an insecure default configuration caused by enabled insecure options including ALLOW_CLIENT_RENEGOTIATION, NO_EXTENDED_MASTER_SECRET, IGNORE_UNEXPECTED_EOF, and ALLOW_NO_DHE_KEX, letting attackers exploit weakened security, exploit requires no special conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-86246/
---

# CVE-2026-86246 Apache Tomcat Native - Insecure Default Configuration

Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 contain an insecure default configuration caused by enabled insecure options including ALLOW\_CLIENT\_RENEGOTIATION, NO\_EXTENDED\_MASTER\_SECRET, IGNORE\_UNEXPECTED\_EOF, and ALLOW\_NO\_DHE\_KEX, letting attackers exploit weakened security, exploit requires no special conditions.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.36% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-86246)

## Details

Type

Insecure Default Configuration

Impact

Man In The Middle

CVSS vector

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

Published

23 September 2026

Updated

15 October 2026

Weakness

[CWE-1188](https://cwe.mitre.org/data/definitions/1188.html)

## Vendor fix

Upgrade to version 2.0.16 or 1.3.9 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-86246](https://nvd.nist.gov/vuln/detail/CVE-2026-86246)
- [https://lists.apache.org/thread/dgyvfwb24nbk45ptvlhdyhdhl5o7k5ol](https://lists.apache.org/thread/dgyvfwb24nbk45ptvlhdyhdhl5o7k5ol)
- [http://www.openwall.com/lists/oss-security/2026/09/23/32](http://www.openwall.com/lists/oss-security/2026/09/23/32)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)