# CVE-2026-86531: Apache OpenEJB HTTP server resource exhaustion

Source: https://junglewise.ai/threats/cve-2026-86531-the-embedded-openejb-http-server-does-not-limit-the-size-of  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-86531 · Severity: info · Published 2026-11-10

The embedded HTTP server in Apache OpenEJB does not properly limit the size of incoming request bodies or multipart uploads, and fails to clean up temporary files created during multipart request processing. A remote attacker can send large requests to exhaust server memory or disk space, causing service disruption. Organizations using Tomcat connectors are not affected.

Technologies: [Apache OpenEJB](https://junglewise.ai/threats/technologies/openejb). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-86531 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86531 being exploited in the wild.

**How severe is CVE-2026-86531?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Apache OpenEJB <unknown>.

**Is there a fix for CVE-2026-86531?** No fixed version is recorded yet. Block network access to the embedded OpenEJB HTTP server from untrusted clients, or migrate to Tomcat-based TomEE distributions which are not affected. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86531 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-86531?** Check whether you run Apache OpenEJB 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.

## How to fix


Block network access to the embedded OpenEJB HTTP server from untrusted clients, or migrate to Tomcat-based TomEE distributions which are not affected.

## Technical details

The OpenEJB embedded HTTP server lacks input size limits on request bodies and multipart form data, and does not remove temporary files created during multipart request handling. An unauthenticated remote attacker can exploit this via network access to trigger denial of service through resource exhaustion (memory or disk). The vulnerability does not affect Tomcat-based TomEE deployments.

## Affected products

- Apache OpenEJB <unknown>

## Timeline

- 2026-11-10: disclosed

## References

- [https://repo.maven.apache.org/maven2](https://repo.maven.apache.org/maven2)
- [https://lists.apache.org/thread/cm1vdbx03ctl607nrrkdqyshwjscpd2y](https://lists.apache.org/thread/cm1vdbx03ctl607nrrkdqyshwjscpd2y)

## Related threats

- [Apache OpenEJB embedded HTTP server privilege escalation via thread identity reuse](https://junglewise.ai/threats/cve-2026-97888-the-embedded-http-server-does-not-clear-the-security-identity)
- [Apache OpenEJB path traversal in HTTP server](https://junglewise.ai/threats/cve-2026-97881-the-embedded-openejb-http-server-does-not-restrict-static)
- [Apache OpenEJB HTTP server authentication bypass in REST endpoints](https://junglewise.ai/threats/cve-2026-97880-the-embedded-openejb-http-server-dispatches-some-requests-to-rest)
- [Apache OpenEJB authentication bypass in embedded HTTP server](https://junglewise.ai/threats/cve-2026-111256-when-jax-ws-or-jax-rs-endpoints-are-published-by-the-embedded)
- [Apache OpenEJB admin service authentication bypass](https://junglewise.ai/threats/cve-2026-111251-the-admin-service-of-the-standalone-openejb-server-accepts-stop)