Quick answers
- Is CVE-2026-91388 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91388 being exploited in the wild.
- How severe is CVE-2026-91388?
- Medium severity, with a CVSS score of 4.7, published 20 October 2026.
- Which products and versions are affected?
- Oracle Siebel CRM End User 17.0 through 26.9.
- Is there a fix for CVE-2026-91388?
- 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-2026-91388 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-91388?
- 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
The vulnerability is a client-side flaw in the Open UI component that can be exploited via HTTP by an unauthenticated network attacker. It requires user interaction (social engineering) and has changed scope, meaning successful exploitation can impact systems beyond Siebel CRM End User itself. Successful attacks grant unauthorized read access to a subset of data and unauthorized create/update/delete access to some accessible data in the CRM.
Affected products
- Oracle Siebel CRM End User 17.0 through 26.9
Timeline
- 2026-10-20: disclosed