CVE-2026-20230

Cisco Unified Communications Manager Server-Side Request Forgery Vulnerability

Published Jun 3, 2026 CVSS 3.1 · 8.6 High EPSS 88.5% KEV · Listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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. 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.
Title SSRF Vulnerability in Cisco Unified Communications Manager Allows Privilege Escalation Cisco Unified Communications Manager Server-Side Request Forgery Vulnerability
Type Values Removed Values Added
Title SSRF Vulnerability in Cisco Unified Communications Manager Allows Privilege Escalation
Type Values Removed Values Added
Title SSRF Vulnerability in Cisco Unified Communications Manager Enabling Privilege Escalation
Type Values Removed Values Added
Title SSRF Vulnerability in Cisco Unified Communications Manager Enabling Privilege Escalation
Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'active', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics kev

{'dateAdded': '2026-06-25T00:00:00+00:00', 'dueDate': '2026-06-28T00:00:00+00:00'}

Type Values Removed Values Added
Title Server‑Side Request Forgery in Cisco Unified Communications Manager Enables Privilege Escalation
Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Server‑Side Request Forgery in Cisco Unified Communications Manager Enables Privilege Escalation
Type Values Removed Values Added
Title SSRF Enabling Arbitrary File Write and Privilege Escalation in Cisco Unified Communications Manager
Type Values Removed Values Added
Title SSRF Enabling Arbitrary File Write and Privilege Escalation in Cisco Unified Communications Manager
Type Values Removed Values Added
Title SSRF Vulnerability Allowing File Write and Root Privilege Escalation in Cisco Unified Communications Manager
Type Values Removed Values Added
Title SSRF Vulnerability Allowing File Write and Root Privilege Escalation in Cisco Unified Communications Manager
Type Values Removed Values Added
Title Server‑Side Request Forgery allows privilege escalation via WebDialer in Cisco Unified Communications Manager
Type Values Removed Values Added
Title Server‑Side Request Forgery allows privilege escalation via WebDialer in Cisco Unified Communications Manager
Type Values Removed Values Added
Title Server‑Side Request Forgery Enabling Root Privileges in Cisco Unified Communications Manager
Type Values Removed Values Added
Title Server‑Side Request Forgery Enabling Root Privileges in Cisco Unified Communications Manager
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cisco
Cisco cisco Unified Communications Manager
Vendors & Products Cisco
Cisco cisco Unified Communications Manager
Type Values Removed Values Added
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.
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
cisco
Published
Updated
Oct 7, 2026, 6:09 PM
Reserved
Oct 8, 2025, 11:59 AM
Status
Analyzed
Published
Jun 3, 2026, 6:16 PM
Modified
Oct 7, 2026, 7:17 PM