---
id: "CVE-2026-91253"
kind: "vulnerability"
aliases: ["CVE-2026-91253"]
title: "Oracle Solaris 11.4 kernel flaw lets local users take over the system"
severity: "high"
cvss: 7.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "on-prem", "oracle", "solaris"]
not_affected_if: ["no-local-logins", "no-solaris-11.4"]
published_at: "2026-10-20T22:20:26+00:00"
first_seen_at: "2026-10-23T21:57:26+00:00"
updated_at: "2026-10-25T03:08:48+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91253", "first_seen_at": "2026-10-23T21:57:26+00:00"}]
---

# Oracle Solaris 11.4 kernel flaw lets local users take over the system

A flaw in the Solaris 11.4 kernel lets a low-privileged local user with logon access compromise the operating system. A successful attack can give full takeover, with high impact to confidentiality, integrity and availability.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `uname -v` on each Solaris host to see the release build.
- Run `pkg info entire` to list the installed Solaris 11.4 package version.
- Check whether untrusted or shared local user accounts exist on the host.

## Fix

- Apply the Oracle Solaris 11.4 kernel security update from Oracle's Critical Patch Update for the period this CVE was published (exact patch id unknown from sources).
- Reboot into the updated boot environment after install.

## Timeline

- 2026-10-23T21:57:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91253

## From the sources

Vulnerability in the Oracle Solaris product of Oracle Systems (component: Kernel).   The supported version that is affected is 11.4. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Oracle Solaris executes to compromise Oracle Solaris.  Successful attacks of this vulnerability can result in takeover of Oracle Solaris. CVSS 3.1 Base Score 7.8 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_