CVE-2026-20045: Cisco Unified Communications Products Code Injection Vulnerability

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.

Description quoted from the CVE record (assigned by cisco, published 2026-01-21).

Weakness: Improper Control of Generation of Code (‘Code Injection’)

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity low, availability none. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since

2026-01-21

US federal deadline

2026-02-11

Ransomware use

Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-00706, CNNVD-202601-3420, EUVD-2026-3600, GHSA-h4w3-hxw6-99q7

VEDAS cluster: VEDAS:GATLINGGATOR

Exploit Observer links 3 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (3)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

• Code repository: https://github.com/ashwesker/ashwesker-cve-2026-20045
• Code repository: https://github.com/dkstar11q/ashwesker-cve-2026-20045
• Code repository: https://github.com/zaryouhashraf/cve-2026-20045

Research and write-ups (1)

• Research or write-up: https://socprime.com/blog/cve-2026-20045-vulnerability

Vulnerability databases and vendor advisories (7)

Catalogue entries, not exploit evidence.

• Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-3600
• Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-h4w3-hxw6-99q7
• Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-20045
• Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20045
• Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202601-3420
• Vulnerability database or vendor advisory: https://www.secpod.com/blog/cisco-unified-cm-and-webex-security-alert-active-zero-day-cve-2026-20045-fixed
• Vulnerability database or vendor advisory: https://www.tenable.com/cve/CVE-2026-20045

25 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS

0.045
some chance of attack soon

VEDAS

0.966
strong exploit evidence

On CISA KEV

Yes, since 2026-01-21

Detection rule

None yet

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.

Who is affected

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: cisco unified_communications_manager, cisco unified_communications_manager_im_and_presence_service, cisco unity_connection, cisco_systems,_inc. cisco_unified_communications_manager, cisco_systems,_inc. cisco_unified_communications_manager_sme, cisco_systems,_inc. unified_communications_manager_im_and_presence_service, cisco_systems,_inc. unity_connection.

How to fix it

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

Vendor guidance:

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voice-rce-mORhqY4b
• https://nvd.nist.gov/vuln/detail/CVE-2026-20045

How to detect it

There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.

References

Government sources

• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20045 (government-resource)

Other references

• cisco-sa-voice-rce-mORhqY4b

Other databases

• CVE record (cve.org)
• NVD
• Exploit Observer

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.