Quick answers
- Is CVE-2026-91658 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91658 being exploited in the wild.
- How severe is CVE-2026-91658?
- Critical severity, with a CVSS score of 9.9, published 20 October 2026.
- Which products and versions are affected?
- Oracle Essbase 21.8.3.0.0.
- Is there a fix for CVE-2026-91658?
- 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-2026-91658 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-91658?
- 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 a low-privileged attacker with network access via HTTP to escalate privileges and achieve system compromise. The vulnerability exhibits scope change, meaning successful exploitation can impact confidentiality, integrity, and availability not only of Essbase but potentially of downstream systems. A fix has not yet been publicly documented in the advisory.
Affected products
- Oracle Essbase 21.8.3.0.0
Timeline
- 2026-10-20: disclosed
- 2026-10-20: advisory