CVE-2026-20045 Cisco Unified Communications Products Code Injection Vulnerability
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 contain a code injection vulnerability that could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 21 Jan 2026.
- Rated High severity (CVSS 8.2, scored by Vendor).
- It has been in the catalogue for 289 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
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.
Affected Versions
| Product | Versions |
|---|---|
| Cisco Cisco Unified Communications Manager | 12.5(1)SU2 12.5(1)SU1 12.5(1) 12.5(1)SU3 12.5(1)SU4 14 |
| Cisco Cisco Unified Communications Manager IM and Presence Service | 12.5(1) 12.5(1)SU1 12.5(1)SU2 12.5(1)SU3 12.5(1)SU4 14 |
| Cisco Cisco Unity Connection | 12.5(1) 12.5(1)SU1 12.5(1)SU2 12.5(1)SU3 12.5(1)SU4 14 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Cisco Unified Communications Manager. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2026-20045 and every other exploited flaw on the list.