CVE-2026-20230
HIGH · 8.6 KEV EPSS 41.7%Working PoC public, honeypot-confirmed attacks, Cisco urgent patching; KEV not listed yet but all indicators signal weaponization.
What: Unauthenticated server-side request forgery (SSRF) in Cisco Unified Communications Manager WebDialer enabling file write and privilege escalation to root; CVSS 8.6, EPSS 97th percentile.
Why it matters: Active in-the-wild exploitation confirmed by honeypot telemetry showing full-chain RCE and webshell deployment; public exploit code available; Cisco issued Critical SIR advisory and released patches (14SU6, 15SU5); high EPSS score reflects rapid weaponization post-disclosure. WebDialer disabled by default but widely enabled in production.
Where it's seen: Security news outlets, threat intel feeds, and defender communities reporting automated attack sweeps via Tor; researchers documenting same-day weaponization; international advisories (Portugal flagged); practitioners debating EPSS vs. CVSS relevance for triage.
RISK: CRITICAL — Active exploitation, privilege escalation to root, patches available but require immediate deployment.
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N- Attack vector
- Network
- Complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None