Actively exploited in the wild
Cisco Unified Communications Manager Server-Side Request Forgery (SSRF) Vulnerability
Cisco — Unified Communications Manager · Listed in the CISA KEV since 2026-06-25. This indicates confirmed attacks in production environments.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CVE-2026-20230
HighCVSS 8.6KEVExploitation Probability (EPSS)
Very high risk99th percentile — higher than 99% of all known CVEs
Summary
A vulnerability in Cisco Unified Communications Manager and Unified CM SME allows an unauthenticated, remote attacker to perform SSRF attacks. The flaw is due to improper input validation for specific HTTP requests, enabling file writes to the OS and potential privilege escalation to root.
Risk Assessment
The organization faces a risk of complete device compromise, with an attacker able to gain root privileges. The WebDialer service must be enabled (disabled by default), but its activation significantly increases the risk of a critical security breach.
Recommendation
Apply the Cisco-provided patch immediately and ensure the WebDialer service is disabled if not required. Regularly monitor Cisco security advisories.
Original NVD description (English source)
A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to conduct server-side request forgery (SSRF) attacks through an affected device. This vulnerability is due to improper input validation for specific HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to write files to the underlying operating system that could be used later to elevate 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. Note: To exploit this vulnerability, the WebDialer service must be enabled. WebDialer is disabled by default.