CVE-2026-20230 | Cisco Unified Communications Manager Server-Side Request Forgery Vulnerability

Exp

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.

Published: 2026-06-03 Last update: 2026-07-22 Assigner: [email protected] Source: [email protected]

NVD Status：Analyzed，CVE State: published

View at NVD, CVE.org, EUVD

Threat Intelligence & Risk Assessment for CVE-2026-20230

KEV EPSS CVSS CWE GHSA Exploit-DB Affected

Conclusion & alert: CVE-2026-20230 is rated Critical Active Threat (88.9/100): CVSS High severity, with high exploitation likelihood (EPSS 41.69%, 99th percentile). Core evidence: CISA KEV confirms active exploitation (added 2026-06-25) affecting Cisco / Unified Communications Manager. a weakness (CWE-918) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2026-20230

Name: Cisco Unified Communications Manager Server-Side Request Forgery (SSRF) Vulnerability · CISA KEV detail

Exploit added: 2026-06-25

Action due: 2026-06-28

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.

Public exploit references (Exploit-DB) for CVE-2026-20230

EDB-ID	Source	Kind	Published	Link
—	nvd_ref	exploit_tag		Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-20230

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-27	51.24%	41.69%	-9.54%
2	2026-06-26	34.16%	51.24%	+17.08%
3	2026-06-25	—	34.16%	—

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20230

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.6	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	3.9	4.0	[email protected]

Weakness enumeration for CVE-2026-20230

CWE-918 MITRE ↗

GitHub Security Advisory for CVE-2026-20230

GHSA-fcv7-pchj-75c2 · Severity: high — A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified...

Affected software / configurations for CVE-2026-20230

Vendor	Product	Version	Raw CPE
cisco	unified_communications_manager	>= 14.0, < 14su6	cpe:2.3:a:cisco:unified_communications_manager:::::-:::*
cisco	unified_communications_manager	>= 14.0, < 14su6	cpe:2.3:a:cisco:unified_communications_manager:::::session_management:::*
cisco	unified_communications_manager	>= 15.0, <= 15su4a	cpe:2.3:a:cisco:unified_communications_manager:::::-:::*
cisco	unified_communications_manager	>= 15.0, <= 15su4a	cpe:2.3:a:cisco:unified_communications_manager:::::session_management:::*

References for CVE-2026-20230

URL	Tags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-ssrf-cXPnHcW	Vendor Advisory
https://denizhalil.com/2026/06/12/cve-2026-20230-cisco-unified-cm-ssrf/	Exploit Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20230	US Government Resource

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