---
id: "CVE-2026-20045"
kind: "vulnerability"
aliases: ["CVE-2026-20045"]
title: "A vulnerability in Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "cisco unified communications manager", "fixed": ["14su5"], "affected": ">= 12.5, < 14su5", "ecosystem": "vendor"}, {"name": "cisco unified communications manager", "fixed": [], "affected": ">= 15.0, <= 15su3a", "ecosystem": "vendor"}, {"name": "cisco unified communications manager im and presence service", "fixed": ["14su5"], "affected": ">= 12.5, < 14su5", "ecosystem": "vendor"}, {"name": "cisco unified communications manager im and presence service", "fixed": [], "affected": ">= 15.0, <= 15su3a", "ecosystem": "vendor"}, {"name": "cisco unity connection", "fixed": ["14su5"], "affected": ">= 12.5, < 14su5", "ecosystem": "vendor"}, {"name": "cisco unity connection", "fixed": [], "affected": ">= 15.0, <= 15su3", "ecosystem": "vendor"}, {"name": "Cisco Unified Communications Manager", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["cisco-unified-cm", "cisco-unity-connection", "exploited", "infrastructure", "on-prem-voice", "webex-calling-dedicated-instance"]
not_affected_if: ["cisco-cloud-only-webex"]
published_at: "2026-01-21T00:00:00+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:50+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20045", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20045", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

# A vulnerability in Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session…

Cisco Unified Communications Manager, Unity Connection and related Cisco voice products contain a code injection flaw. An attacker can get user-level shell access on the underlying operating system and then escalate to root.

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

## Affected

- vendor:cisco unified communications manager affected >= 12.5, < 14su5 fixed 14su5
- vendor:cisco unified communications manager affected >= 15.0, <= 15su3a fixed ?
- vendor:cisco unified communications manager im and presence service affected >= 12.5, < 14su5 fixed 14su5
- vendor:cisco unified communications manager im and presence service affected >= 15.0, <= 15su3a fixed ?
- vendor:cisco unity connection affected >= 12.5, < 14su5 fixed 14su5
- vendor:cisco unity connection affected >= 15.0, <= 15su3 fixed ?
- vendor:Cisco Unified Communications Manager affected ? fixed ?

## How to check

Confirm which Cisco Unified CM, CM SME, IM&P, Unity Connection or Webex Calling Dedicated Instance versions you run, using the product admin interface.

## Fix

Apply the Cisco mitigation or fixed release from the Cisco security advisory for CVE-2026-20045; the sources do not name the version.
If no mitigation is available, follow CISA guidance and discontinue use of the product.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20045
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-20045

## From the sources

A vulnerability in Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session Management Edition (Unified CM SME), Cisco Unified Communications Manager IM &amp; Presence Service (Unified CM IM&amp;P), Cisco Unity Connection, and Cisco Webex Calling Dedicated Instance could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device.&nbsp;

This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending a sequence of crafted HTTP requests to the web-based management interface of an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root.&nbsp;
Note: Cisco has assigned this security advisory a Security Impact Rating (SIR) of Critical rather than High as the score indicates. The reason is that exploitation of this vulnerability could result in an attacker elevating privileges to root.

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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_