Zero-day vulnerability in Cisco Unified Communications Manager

Code Injection
CVE-2026-20045

Vulnerability details

Advisory: SB2026012157 - Unauthenticated remote code execution in Cisco Unified Communications products

Vulnerable component: Cisco Unified Communications Manager

CVE-ID: CVE-2026-20045

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Description:

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation when handling HTTP requests. A remote attacker can send a specially crafted HTTP request and execute arbitrary code on the target system.

Note, the vulnerability is being actively exploited in the wild.

External links:

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voice-rce-mORhqY4b

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.