# CVE-2026-87289: Oracle Helidon webserver static content denial of service

Source: https://junglewise.ai/threats/cve-2026-87289-oracle-helidon-webserver-static-content-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-15. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-87289 · Severity: high · CVSS 7.5 · Published 2026-09-15

Oracle Helidon is an open-source microservices framework used to build lightweight Java applications. A denial-of-service vulnerability in its static content serving component allows unauthenticated attackers to remotely crash or hang the Helidon server via HTTP requests, disrupting application availability without requiring authentication or user interaction.

Technologies: [Oracle Helidon](https://junglewise.ai/threats/technologies/helidon). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-87289 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-87289 being exploited in the wild.

**How severe is CVE-2026-87289?** High severity, with a CVSS score of 7.5, published 15 September 2026.

**Which products and versions are affected?** Oracle Helidon 4.0.0 to 4.5.4.

**Is there a fix for CVE-2026-87289?** No fixed version is recorded yet. Check the vendor's advisory in the references below. 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-2026-87289 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-87289?** Check whether you run Oracle Helidon 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

This vulnerability exists in the helidon-webserver-static-content component of Helidon versions 4.0.0 through 4.5.4. The flaw is easily exploitable and allows an unauthenticated attacker with network access to send crafted HTTP requests that cause a hang or repeated crash of the affected server, resulting in denial of service. The attack requires no privileges, no special configuration, and no user interaction. The vulnerability impacts only availability; there is no impact to confidentiality or integrity. Patches are expected to be available from Oracle.

## Affected products

- Oracle Helidon 4.0.0 to 4.5.4

## Timeline

- 2026-09-15: disclosed

## References

- [https://www.oracle.com/security-alerts/cspusep2026.html](https://www.oracle.com/security-alerts/cspusep2026.html)

## Related threats

- [Oracle Helidon microprofile-security authentication bypass](https://junglewise.ai/threats/cve-2026-101590-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware)
- [Oracle Helidon WebSocket unauthenticated information disclosure](https://junglewise.ai/threats/cve-2026-101588-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware)
- [Oracle Helidon denial of service in webclient HTTP/1](https://junglewise.ai/threats/cve-2026-101587-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware)
- [Oracle Helidon information disclosure in helidon-webclient](https://junglewise.ai/threats/cve-2026-101586-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware)
- [Oracle Helidon CORS authorization bypass in helidon-cors](https://junglewise.ai/threats/cve-2026-101585-vulnerability-in-the-helidon-product-of-oracle-fusion-middleware)