CVE-2026-20230

CVE-2026-20230 is a high-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 8.6. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-06-25). The underlying weakness is classified as CWE-918.

Key facts

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.

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 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-20230 being actively exploited?
Yes. CVE-2026-20230 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-06-25, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-20230?
CVE-2026-20230 primarily affects Cisco Unified Communications Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20230?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2026-20230 have an EU (EUVD) identifier?
Yes. CVE-2026-20230 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34137. It is also flagged as exploited in the EUVD (since 2026-06-25).
When was CVE-2026-20230 published?
CVE-2026-20230 was published on 2026-06-03 and last updated on 2026-07-01.

References

Affected products (2)

More vulnerabilities in Cisco Unified Communications Manager

All CVEs affecting Cisco Unified Communications Manager →

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities

Browse all CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities →