---
id: "CVE-2026-91366"
kind: "vulnerability"
aliases: ["CVE-2026-91366"]
title: "Oracle Siebel CRM Cloud: adjacent-network flaw allows limited data read and write"
severity: "medium"
cvss: 4.7
epss: 0.00147
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["crm", "oracle", "self-hosted", "siebel", "vendor"]
not_affected_if: ["internet-only-access", "managed-hosting"]
published_at: "2026-10-20T22:20:39+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-2026-91366", "first_seen_at": "2026-10-23T21:57:26+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91366", "first_seen_at": "2026-10-25T12:38:52+00:00"}]
---

# Oracle Siebel CRM Cloud: adjacent-network flaw allows limited data read and write

Oracle Siebel CRM Cloud Applications, via the Siebel Cloud Manager component, has a flaw that lets an unauthenticated attacker on the physical network segment of the hardware alter or delete some accessible data and read a subset of it. The attack is hard to carry out and needs adjacent network access rather than internet access.

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

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91366
- 2026-10-25T12:38:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91366

## From the sources

Vulnerability in the Siebel CRM Cloud Applications product of Oracle Siebel CRM (component: Siebel Cloud Manager).  Supported versions that are affected are 22.3-26.9. Difficult to exploit vulnerability allows unauthenticated attacker with access to the physical communication segment attached to the hardware where the Siebel CRM Cloud Applications executes to compromise Siebel CRM Cloud Applications.  While the vulnerability is in Siebel CRM Cloud Applications, attacks may significantly impact additional products (scope change).  Successful attacks of this vulnerability can result in  unauthorized update, insert or delete access to some of Siebel CRM Cloud Applications accessible data as well as  unauthorized read access to a subset of Siebel CRM Cloud Applications accessible data. CVSS 3.1 Base Score 4.7 (Confidentiality and Integrity impacts).  CVSS Vector: (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/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_