---
id: "CVE-2026-91435"
kind: "vulnerability"
aliases: ["CVE-2026-91435"]
title: "Oracle Siebel CRM: low-privileged HTTP request can crash the server"
severity: "medium"
cvss: 6.5
epss: 0.00394
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["enterprise-crm", "oracle", "self-hosted", "siebel-crm", "vendor"]
not_affected_if: ["http-not-exposed", "no-siebel-deployment"]
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-2026-91435", "first_seen_at": "2026-10-23T21:57:26+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91435", "first_seen_at": "2026-10-25T12:38:52+00:00"}]
---

# Oracle Siebel CRM: low-privileged HTTP request can crash the server

Oracle Siebel CRM Deployment's Server Infrastructure component has a flaw that lets a low-privileged user over HTTP cause a hang or repeatable crash of the service. The sources describe a denial of service only, with no code execution or data exposure.

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

## How to check

- Confirm the Siebel CRM Deployment version in use; the sources list supported versions 17.0 through 26.9 as affected.
- Check the Oracle Critical Patch Update advisory for the patch level covering this CVE; the sources do not name the fixed build.

## Fix

- Apply the Oracle Siebel CRM security patch for CVE-2026-91435 from the Oracle Critical Patch Update; the fixed version is unknown from the sources.
- Restrict HTTP access to Siebel server endpoints to trusted networks until patched.

## Timeline

- 2026-10-23T21:57:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91435
- 2026-10-25T12:38:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91435

## From the sources

Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure).  Supported versions that are affected are 17.0-26.9. Easily exploitable vulnerability allows low privileged attacker with network access via HTTP to compromise Siebel CRM Deployment.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Siebel CRM Deployment. CVSS 3.1 Base Score 6.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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_