---
id: "CVE-2026-91537"
kind: "vulnerability"
aliases: ["CVE-2026-91537"]
title: "Oracle Solaris 11.4: Utility flaw lets a local user take over the system"
severity: "high"
cvss: 7.8
epss: 0.00118
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "on-prem", "oracle", "os", "solaris"]
not_affected_if: ["no-untrusted-local-logins"]
published_at: "2026-10-20T22:20:57+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T12:38:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91537", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91537", "first_seen_at": "2026-10-25T12:38:51+00:00"}]
---

# Oracle Solaris 11.4: Utility flaw lets a local user take over the system

A flaw in the Utility component of Oracle Solaris 11.4 lets an attacker with a low-privileged local login compromise the operating system. Successful exploitation gives the attacker 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 the host and check whether it reports Solaris 11.4.
- Check the installed Solaris release with `pkg info entire` and compare against the fixed build in Oracle's advisory.
- unknown for exact fixed versions: the sources do not say which patch level resolves it.

## Fix

- Apply the Oracle Solaris 11.4 security patch or SRU that addresses this CVE, per Oracle's Critical Patch Update.
- Limit local shell access to trusted accounts until patched.
- unknown for the specific fixed build: the sources do not name it.

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91537
- 2026-10-25T12:38:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91537

## From the sources

Vulnerability in the Oracle Solaris product of Oracle Systems (component: Utility).   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).

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