Prioritize patching. It under exploitation confirmed by CISA and has a public proof of concept.
ssvc Actcvss 8.6epss 88%
from disclosure to weapon2 days
Published on NVDJun 3
1st PoC+2d
CISA KEV+22d
exploitation probability
88%top 1% of all CVEs
observed exploitation
yesCISA + VulnCheck
5 public exploit(s)
Action required by CISAfederal deadline: 2026-06-28
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.
In short
A flaw in Cisco Unified Communications Manager allows attackers to send specially crafted requests that trick the server into accessing internal resources and writing files to the system. This could let an attacker gain complete control (root access) of the affected device.
Technical detail
SSRF vulnerability in Cisco Unified CM and Unified CM SME due to improper HTTP input validation. Unauthenticated remote attacker can send crafted HTTP requests via the WebDialer service (when enabled) to write files to the underlying OS, enabling privilege escalation to root. Attack requires WebDialer to be active but no authentication is needed.
Summary generated and translated by AI from the official description.
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.