Cisco Unified Communications Manager Server-Side Request Forgery (SSRF) Vulnerability
Cisco — Cisco Unified Communications Manager
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.
8.6
88.2%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
- Published
- Jun 3, 2026
- Modified
- Oct 7, 2026
- Added to KEV
- Jun 25, 2026
- Federal patch due
- Jun 28, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2026-20230, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2026-20230 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.
References
How this class of flaw gets exploited
Frequently asked questions
What is CVE-2026-20230?
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.
How severe is CVE-2026-20230?
CVE-2026-20230 has a CVSS base score of 8.6 out of 10 (CVSS 3.1).
Is CVE-2026-20230 actively exploited in the wild?
Yes. CVE-2026-20230 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jun 25, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-20230?
88.2% - meaning FIRST.org's EPSS model estimates a 88.2% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
What type of vulnerability is CVE-2026-20230?
CVE-2026-20230 is classified under CWE-918 (Server-Side Request Forgery (SSRF)).
Cross-checked against
Impactr finds and proves whether CVE-2026-20230 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.