How severe is CVE-2026-91256?

High severity. CVSS v3 base score is 7.1 out of 10.

Vulnerability in Oracle Corporation Solaris

CVE-2026-91256

Vulnerability in the Oracle Solaris product of Oracle Systems (component: Services). The supported version that is affected is 11.4. Easily exploitable vulnerability allows low privileged attacker with network access via HTTP to compromise Oracle Solaris. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Solaris and unauthorized read access to a subset of Oracle Solaris accessible data. CVSS 3.1 Base Score 7.1 (Confidentiality and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H).

Published 2026-10-20 · last modified 2026-10-21.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Oracle Corporation Solaris — versions 11.4

References

www.oracle.com/security-alerts/cpuoct2026.html (vendor-advisory)

Frequently asked questions

What is CVE-2026-91256?: CVE-2026-91256 is a high-severity vulnerability in Oracle Corporation Solaris. CVSS score: 7.1/10. Published 2026-10-20.
How severe is CVE-2026-91256?: High severity. CVSS v3 base score is 7.1 out of 10.