# CVE-2026-91664: Oracle Essbase denial of service in Security component

Source: https://junglewise.ai/threats/cve-2026-91664-vulnerability-in-oracle-essbase-component-security-the-supported  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-91664 · Severity: high · CVSS 7.5 · Published 2026-10-20

Oracle Essbase is a business analytics and planning platform used by enterprises to consolidate financial and operational data. An unauthenticated attacker can remotely cause the Essbase service to crash or hang indefinitely, disrupting business operations and data availability. The vulnerability requires only network access and can be triggered without any user interaction.

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

## Quick answers

**Is CVE-2026-91664 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91664 being exploited in the wild.

**How severe is CVE-2026-91664?** High severity, with a CVSS score of 7.5, published 20 October 2026.

**Which products and versions are affected?** Oracle Essbase 21.8.3.0.0.

**Is there a fix for CVE-2026-91664?** 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-2026-91664 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-91664?** Check whether you run Oracle Essbase 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

An easily exploitable vulnerability in the Security component of Oracle Essbase allows unauthenticated attackers with network access to trigger a denial of service condition. The flaw can be exploited via TCP without authentication or user interaction, causing the application to hang or crash repeatedly. The vulnerability impacts only availability.

## Affected products

- Oracle Essbase 21.8.3.0.0

## Timeline

- 2026-10-20: disclosed

## References

- [https://www.oracle.com/security-alerts/cpuoct2026.html](https://www.oracle.com/security-alerts/cpuoct2026.html)

## Related threats

- [Oracle Essbase unauthenticated remote code execution](https://junglewise.ai/threats/cve-2026-91665-vulnerability-in-oracle-essbase-component-security-the-supported)
- [Oracle Essbase privilege escalation in Security component](https://junglewise.ai/threats/cve-2026-91663-vulnerability-in-oracle-essbase-component-security-the-supported)
- [Oracle Essbase privilege escalation in Java Based Agent](https://junglewise.ai/threats/cve-2026-91662-vulnerability-in-oracle-essbase-component-java-based-agent-the)
- [Oracle Essbase authentication bypass in security component](https://junglewise.ai/threats/cve-2026-91661-vulnerability-in-oracle-essbase-component-security-the-supported)
- [Oracle Essbase denial of service in Security component](https://junglewise.ai/threats/cve-2026-91660-vulnerability-in-oracle-essbase-component-security-the-supported)