Critical Cisco Unified CM Vulnerability CVE-2026-20230 Exploited in the Wild
In June 2026, a critical server-side request forgery (SSRF) vulnerability, identified as CVE-2026-20230, was discovered in Cisco Unified Communications Manager (Unified CM) and Unified CM Session Management Edition (SME). This flaw allows unauthenticated remote attackers to send crafted HTTP requests, enabling arbitrary file writes to the underlying operating system and potential privilege escalation to root. The vulnerability specifically affects deployments with the WebDialer service enabled, which is disabled by default. Cisco has assigned a Security Impact Rating of Critical due to the severity of the potential exploit. The public availability of proof-of-concept exploit code has led to active exploitation of this vulnerability in the wild. Organizations using affected Cisco Unified CM versions are urged to apply the provided patches immediately or disable the WebDialer service to mitigate the risk of unauthorized access and control over their telephony infrastructure.
Kill Chain