---
id: "CVE-2026-91431"
kind: "vulnerability"
aliases: ["CVE-2026-91431"]
title: "Oracle Siebel CRM End User: low-privilege local flaw exposes critical data"
severity: "medium"
cvss: 5.5
epss: 0.00109
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["enterprise-crm", "oracle", "siebel-crm", "vendor"]
not_affected_if: ["unaffected-version"]
published_at: "2026-10-20T22:20:46+00:00"
first_seen_at: "2026-10-23T21:57:26+00:00"
updated_at: "2026-10-25T12:38:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91431", "first_seen_at": "2026-10-23T21:57:26+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91431", "first_seen_at": "2026-10-25T12:38:52+00:00"}]
---

# Oracle Siebel CRM End User: low-privilege local flaw exposes critical data

Oracle Siebel CRM End User, in the Open UI component, has a flaw that lets an attacker with low-privilege logon to the host reach data they should not see. Successful exploitation can expose critical data or all data accessible to the End User application.

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

## How to check

- Confirm whether Siebel CRM End User is deployed and which version runs, using the product's own version output or the installed build; the sources do not give a command.
- Check whether the deployment is within the affected range `17.0` through `26.9`.

## Fix

- Apply the Oracle Critical Patch Update fix for Siebel CRM End User; the sources do not name the patched build, so unknown.
- Until patched, restrict local logon to the Siebel host to trusted administrators.

## Timeline

- 2026-10-23T21:57:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91431
- 2026-10-25T12:38:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91431

## From the sources

Vulnerability in the Siebel CRM End User product of Oracle Siebel CRM (component: Open UI).  Supported versions that are affected are 17.0-26.9. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Siebel CRM End User executes to compromise Siebel CRM End User.  Successful attacks of this vulnerability can result in  unauthorized access to critical data or complete access to all Siebel CRM End User accessible data. CVSS 3.1 Base Score 5.5 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

---

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