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Active Exploitation of Cisco Unified Communications RCE (CVE-2026-20045)

known exploited vulnerabilitiesactive exploitationprivilege escalationcisco unified communications managerciscozero-dayunified communicationscode injectionvulnerabilityrcewebex calling dedicated instancepatchinguser-supplied inputcisaimproper validation
Updated January 24, 2026 at 01:00 AM11 sources
Active Exploitation of Cisco Unified Communications RCE (CVE-2026-20045)

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Cisco released fixes for a critical remote code execution vulnerability in Unified Communications and Webex Calling Dedicated Instance, tracked as CVE-2026-20045, after it was actively exploited as a zero-day. The issue stems from improper validation of user-supplied input in HTTP requests to the web-based management interface; successful exploitation can provide user-level OS access and enable privilege escalation to root. Affected products include Cisco Unified Communications Manager (Unified CM), Unified CM Session Management Edition (SME), Unified CM IM & Presence, Cisco Unity Connection, and Webex Calling Dedicated Instance; Cisco provided version-specific remediations including fixed releases and .cop patch files (e.g., ciscocm.V14SU4a_CSCwr21851_remote_code_v1.cop.sha512).

CISA added CVE-2026-20045 to its Known Exploited Vulnerabilities (KEV) Catalog, citing evidence of active exploitation and highlighting code injection flaws as a common attack vector with significant risk to the federal enterprise. Under Binding Operational Directive (BOD) 22-01, Federal Civilian Executive Branch agencies are required to remediate KEV-listed vulnerabilities by the specified due date, and CISA urged all organizations to similarly prioritize patching to reduce exposure to ongoing attacks.

Sources

January 23, 2026 at 02:59 PM
January 23, 2026 at 12:00 AM

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