Summary
generated automatically from NVD dataCisco Unified Communications Manager and Unified CM Session Management Edition have a server-side request forgery flaw (CWE-918) caused by improper input validation of specific HTTP requests. An unauthenticated remote attacker could send a crafted request to write files to the underlying operating system, which could later be used to gain root; this requires the WebDialer service, disabled by default, to be enabled. It carries a CVSS v3.1 score of 8.6 (HIGH), Cisco rates it Critical, and CISA lists it in its KEV catalog.
NVD 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.
⚠️ Actively exploited — CISA KEV
This CVE was added to CISA's Known Exploited Vulnerabilities catalog on 2026-06-25. It is confirmed exploited in the wild and must be patched as a priority.
Remediation deadline (US federal agencies): 2026-06-28
EPSS · FIRST.org
88.2%probability of exploitation in the next 30 days
Higher than 99% of scored CVEs
EPSS (Exploit Prediction Scoring System) estimates, from observed exploitation activity, how likely a CVE is to be exploited in the next 30 days. It complements CVSS, which measures severity, not likelihood. Score of 2026-10-19, recomputed daily by FIRST.org.
In-depth analysis on cveo.tech
We've published a detailed analysis of this CVE — exploitation, IOCs and mitigation.
CVSS v3.1 Score
Information
- Published
- 3 juin 2026
- Updated
- 7 oct. 2026
- Status
- Analyzed
- Source
- psirt@cisco.com
Affected products
Weaknesses (CWE)
References (3)
- https://denizhalil.com/2026/06/12/cve-2026-20230-cisco-unified-cm-ssrf/ExploitThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20230US Government Resource
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