# CVE-2026-91428: Oracle Siebel CRM End User Cross-Site Request Forgery in Open UI

Source: https://junglewise.ai/threats/cve-2026-91428-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-91428 · Severity: medium · CVSS 4.3 · Published 2026-10-20

Oracle Siebel CRM is a customer relationship management platform that manages business interactions and data. This vulnerability in the Open UI component allows an attacker to trick a legitimate user into unknowingly modifying or deleting CRM data through a malicious webpage or link. While the flaw requires user interaction, it could lead to unauthorized changes to sensitive business information without the user's knowledge.

Technologies: [Oracle Siebel CRM End User](https://junglewise.ai/threats/technologies/siebel-crm-end-user). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-91428 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91428 being exploited in the wild.

**How severe is CVE-2026-91428?** Medium severity, with a CVSS score of 4.3, published 20 October 2026.

**Which products and versions are affected?** Oracle Siebel CRM End User 17.0-26.9.

**Is there a fix for CVE-2026-91428?** 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-2026-91428 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-91428?** 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

An easily exploitable vulnerability in Siebel CRM End User's Open UI component permits unauthenticated attackers to perform unauthorized data modifications via HTTP. The attack requires social engineering a user to visit a malicious site or click a crafted link, after which the attacker gains write access to some accessible CRM data. The vulnerability affects versions 17.0 through 26.9.

## Affected products

- Oracle Siebel CRM End User 17.0-26.9

## Timeline

- 2026-10-20: disclosed

## References

- [https://www.oracle.com/security-alerts/cpuoct2026.html](https://www.oracle.com/security-alerts/cpuoct2026.html)

## Related threats

- [Oracle Siebel CRM End User unauthorized data access in Communications Panel](https://junglewise.ai/threats/cve-2026-91445-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel)
- [Oracle Siebel CRM End User unauthorized data access in Open UI](https://junglewise.ai/threats/cve-2026-91432-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel)
- [Oracle Siebel CRM End User unauthorized data access in Open UI](https://junglewise.ai/threats/cve-2026-91431-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel)
- [Oracle Siebel CRM End User unauthorized access in Open UI](https://junglewise.ai/threats/cve-2026-91412-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel)
- [Oracle Siebel CRM End User cross-site request forgery in Open UI](https://junglewise.ai/threats/cve-2026-91390-vulnerability-in-the-siebel-crm-end-user-product-of-oracle-siebel)