CVEs / CVE-2026-20230
CVE-2026-20230: Cisco Unified Communications Manager Server-Side Request Forgery (SSRF) Vulnerability
- Known exploited in the CISA KEV catalog since 25 Jun 2026
- high 8.6 CVSS 3.1 (from the CNA)
- EPSS 88.5% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) contain a server-side request forgery (SSRF) Vulnerability that could allow an unauthenticated, remote attacker to write files to the underlying operating system that could be used later to elevate to root.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Cisco Unified Communications Manager | 14 | — |
| Cisco Cisco Unified Communications Manager | 14SU1 | — |
| Cisco Cisco Unified Communications Manager | 14SU2 | — |
| Cisco Cisco Unified Communications Manager | 14SU3 | — |
| Cisco Cisco Unified Communications Manager | 15 | — |
| Cisco Cisco Unified Communications Manager | 15SU1 | — |
| Cisco Cisco Unified Communications Manager | 14SU4 | — |
| Cisco Cisco Unified Communications Manager | 14SU4a | — |
| Cisco Cisco Unified Communications Manager | 15SU1a | — |
| Cisco Cisco Unified Communications Manager | 15SU2 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13010-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13011-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13012-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13013-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13014-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13015-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13016-1 | — |
| Cisco Cisco Unified Communications Manager | 15.0.1.13017-1 | — |
| Cisco Cisco Unified Communications Manager | 15SU3a | — |
| Cisco Cisco Unified Communications Manager | 14SU5 | — |
| Cisco Cisco Unified Communications Manager | 15SU4 | — |
| Cisco Cisco Unified Communications Manager | 15SU4a | — |
Exploitation
| In CISA KEV since | 25 Jun 2026 |
|---|---|
| Due date for US federal agencies | 28 Jun 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 8.6 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-918 |
References
- CVE-2026-20230 on NVD
- CVE-2026-20230 in the CISA KEV catalog
- https://www.cisco.com/c/en/us/support/docs/csa/cisco-sa-cucm-ssrf-cXPnHcW.html (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- 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
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.