Cisco Unified Communications Manager code injection

Summaryinfo

A vulnerability classified as critical was found in Cisco Unified Communications Manager, Unified Communications Manager Session Management Edition, Unified Communications Manager IM & Presence Service, Unity Connection and Webex Calling Dedicated Instance. Impacted is an unknown function. Executing a manipulation can lead to code injection. This vulnerability is registered as CVE-2026-20045. It is possible to launch the attack remotely. Furthermore, an exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Cisco Unified Communications Manager, Unified Communications Manager Session Management Edition, Unified Communications Manager IM & Presence Service, Unity Connection and Webex Calling Dedicated Instance. It has been declared as critical. This vulnerability affects an unknown function. The manipulation with an unknown input leads to a code injection vulnerability. The CWE definition for the vulnerability is CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A vulnerability in Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session Management Edition (Unified CM SME), Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P), Cisco Unity Connection, and Cisco Webex Calling Dedicated Instance could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device.  This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending a sequence of crafted HTTP requests to the web-based management interface of an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges 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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability was named CVE-2026-20045. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are unknown but an exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/19/2026). The MITRE ATT&CK project declares the attack technique as T1059.

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 295030 (Cisco Unity Connection Remote Code Execution (cisco-sa-voice-rce-mORhqY4b)), which helps to determine the existence of the flaw in a target environment. This issue was added on 01/21/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 02/11/2026:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Zero-Day.cz (1063), Tenable (295030), EUVD (EUVD-2026-3600) and CERT Bund (WID-SEC-2026-0192). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Cisco Unified Communications Manager (CUCM)
• Cisco Unified Communications Manager IM & Presence Service
• Cisco Unity Connection

Productinfo

Type

• Unified Communication Software

Vendor

• Cisco

Name

• Unified Communications Manager
• Unified Communications Manager IM & Presence Service
• Unified Communications Manager Session Management Edition
• Unity Connection
• Webex Calling Dedicated Instance

License

• commercial

Website

• Vendor: https://www.cisco.com/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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