Quick answers
- Is CVE-2026-86243 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-86243 being exploited in the wild.
- How severe is CVE-2026-86243?
- High severity, with a CVSS score of 7.5, published 23 September 2026.
- Which products and versions are affected?
- Apache Tomcat Native 1.3.0 through 1.3.8, 2.0.0 through 2.0.15.
- Is there a fix for CVE-2026-86243?
- A patch was published on 2026-09-23: Fixed in Tomcat Native 1.3.9 and 2.0.16 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-86243 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-86243?
- Check whether you run Apache Tomcat Native at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A buffer over-read vulnerability exists in Apache Tomcat Native's TLS handshake processing code, exploitable via a malicious TLS connection. The vulnerability requires network access to a service using the affected library and can be triggered during the handshake phase without authentication, resulting in a JVM crash and application unavailability. Patches are available in versions 1.3.9 and 2.0.16.
Affected products
- Apache Tomcat Native 1.3.0 through 1.3.8, 2.0.0 through 2.0.15
Timeline
- 2026-09-23: disclosed
- 2026-09-23: patched: Fixed in Tomcat Native 1.3.9 and 2.0.16