Exploited Zero-Day Flaw in Cisco UC Could Affect Millions
Mass scanning is underway for CVE-2026-20045, which Cisco tagged as critical because successful exploitation could lead to a complete system takeover.
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 contain a code injection vulnerability that could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root.
Cisco · Unified Communications Manager
Known ransomware use: Unknown
Follow the source advisory and validate exposure in your environment.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Recent reporting that mentions CVE-2026-20045.
Mass scanning is underway for CVE-2026-20045, which Cisco tagged as critical because successful exploitation could lead to a complete system takeover.
Cisco has released fresh patches to address what it described as a "critical" security vulnerability impacting multiple Unified Communications (CM) products and Webex Calling Dedicated Instance that it has been actively exploited as a zero-day in the wild
Cisco has fixed a critical Unified Communications and Webex Calling remote code execution vulnerability, tracked as CVE-2026-20045, that has been actively exploited as a zero-day in attacks. [...]