Quick answers
- Is CVE-2026-91638 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91638 being exploited in the wild.
- How severe is CVE-2026-91638?
- 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-2026-91638?
- 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-2026-91638 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-91638?
- 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
The vulnerability exists in the Essbase security component and is easily exploitable via HTTP by a low-privileged network attacker without user interaction. Successful exploitation results in complete system compromise with impact to confidentiality, integrity, and availability, and has a scope change meaning the attack can affect resources beyond the vulnerable component itself.
Affected products
- Oracle Essbase 21.8.3.0.0
Timeline
- 2026-10-20: disclosed