# CVE-2026-91255: Oracle Solaris kernel denial of service

Source: https://junglewise.ai/threats/cve-2026-91255-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-2026-91255 · Severity: high · CVSS 7.5 · Published 2026-10-20

A vulnerability in the Oracle Solaris kernel allows an unauthenticated attacker on the network to crash the operating system repeatedly or cause it to hang, resulting in complete denial of service. This affects Solaris 11.4 systems accessible over HTTP without requiring authentication or user interaction.

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

## Quick answers

**Is CVE-2026-91255 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91255 being exploited in the wild.

**How severe is CVE-2026-91255?** High severity, with a CVSS score of 7.5, published 20 October 2026.

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

**Is there a fix for CVE-2026-91255?** 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-2026-91255 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-91255?** 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

An easily exploitable network-accessible vulnerability in the Solaris kernel allows unauthenticated remote attackers to trigger resource exhaustion leading to denial of service. The attack vector is HTTP-based with no authentication or privileges required, and successful exploitation causes a system hang or crash impacting availability.

## 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)

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