Quick answers
- Is CVE-2026-91657 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91657 being exploited in the wild.
- How severe is CVE-2026-91657?
- Medium severity, with a CVSS score of 4.3, published 20 October 2026.
- Which products and versions are affected?
- Oracle Essbase 21.8.3.0.0.
- Is there a fix for CVE-2026-91657?
- 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-2026-91657 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-91657?
- 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
A low-privilege authentication bypass or authorization flaw in the HTTP endpoint of Oracle Essbase 21.8.3.0.0 allows network-based attackers to gain unauthorized read access to a subset of accessible data. The vulnerability requires valid credentials but not administrative privileges, and can be triggered without user interaction. No patch status is disclosed in the advisory.
Affected products
- Oracle Essbase 21.8.3.0.0
Timeline
- 2026-10-20: disclosed