# CVE-2026-91209: Oracle Solaris X Window System privilege escalation

Source: https://junglewise.ai/threats/cve-2026-91209-vulnerability-in-the-oracle-solaris-product-of-oracle-systems  
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-2026-91209 · Severity: medium · CVSS 4.2 · Published 2026-10-20

A vulnerability in the X Window System component of Oracle Solaris allows a local user with low-level access to compromise the system, potentially exposing, modifying, or deleting data. Successful exploitation requires tricking another user into taking action, and can result in data breaches, unauthorized changes, and temporary service disruptions on affected systems.

Technologies: [Oracle Solaris](https://junglewise.ai/threats/technologies/solaris). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-91209 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91209 being exploited in the wild.

**How severe is CVE-2026-91209?** Medium severity, with a CVSS score of 4.2, published 20 October 2026.

**Which products and versions are affected?** Oracle Solaris 11.4.

**Is there a fix for CVE-2026-91209?** 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-2026-91209 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-91209?** Check whether you run Oracle Solaris 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

This difficult-to-exploit local privilege escalation in Solaris 11.4's X Window System requires low privileges and user interaction to trigger. An attacker with local system access and low privileges can manipulate X Window System functionality to gain unauthorized read and write access to system data and cause partial denial of service, though successful exploitation is hindered by high attack complexity and requirement for user interaction.

## Affected products

- Oracle Solaris 11.4

## 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 Solaris privilege escalation in utility component](https://junglewise.ai/threats/cve-2026-91537-vulnerability-in-the-oracle-solaris-product-of-oracle-systems)
- [Oracle Solaris privilege escalation in Utility component](https://junglewise.ai/threats/cve-2026-91348-vulnerability-in-the-oracle-solaris-product-of-oracle-systems)
- [Oracle Solaris privilege escalation in Utility component](https://junglewise.ai/threats/cve-2026-91336-vulnerability-in-the-oracle-solaris-product-of-oracle-systems)
- [Oracle Solaris denial of service in Libraries component](https://junglewise.ai/threats/cve-2026-91324-vulnerability-in-the-oracle-solaris-product-of-oracle-systems)
- [Oracle Solaris Services denial of service and information disclosure](https://junglewise.ai/threats/cve-2026-91256-vulnerability-in-the-oracle-solaris-product-of-oracle-systems)