Quick answers
- Is CVE-2026-91387 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91387 being exploited in the wild.
- How severe is CVE-2026-91387?
- Medium severity, with a CVSS score of 5.4, published 20 October 2026.
- Which products and versions are affected?
- Oracle Siebel CRM End User 17.0 to 26.9.
- Is there a fix for CVE-2026-91387?
- 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-2026-91387 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-91387?
- Check whether you run Oracle Siebel CRM End User 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-privileged authenticated attacker can exploit an authorization bypass vulnerability in the Open UI component of Oracle Siebel CRM via HTTP network access without user interaction. The vulnerability allows unauthorized read access to a subset of CRM data and unauthorized update, insert, or delete operations on accessible data. No availability impact is reported, suggesting this is an access control issue rather than a denial-of-service flaw.
Affected products
- Oracle Siebel CRM End User 17.0 to 26.9
Timeline
- 2026-10-20: disclosed