CVE-2026-20045: Cisco Unified Communications Products Code Injection Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2026-01-21. EPSS: 4.5% chance of exploitation in the next 30 days.

A vulnerability in Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session Management Edition (Unified CM SME), Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&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.  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.  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.

Affected products

• Cisco Unified Communications Manager: from 12.5, before 14su5 (fixed in 14su5); from 15.0, up to and including 15su3a
• Cisco Unified Communications Manager Im And Presence Service: from 12.5, before 14su5 (fixed in 14su5); from 15.0, up to and including 15su3a
• Cisco Unity Connection: from 12.5, before 14su5 (fixed in 14su5); from 15.0, up to and including 15su3

Published 2026-01-21. Last modified 2026-06-17.