How severe is CVE-2026-20045?

CVE-2026-20045 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2026-20045 being actively exploited?

Yes. CVE-2026-20045 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-01-21, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-20045?

CVE-2026-20045 primarily affects Cisco Unified Communications Manager. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20045?

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-2026-20045 have an EU (EUVD) identifier?

Yes. CVE-2026-20045 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3600. It is also flagged as exploited in the EUVD (since 2026-01-21).

When was CVE-2026-20045 published?

CVE-2026-20045 was published on 2026-01-21 and last updated on 2026-06-17.

CVE-2026-20045

CVE-2026-20045 is a high-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 8.2. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-01-21). The underlying weakness is classified as CWE-94.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-01-21)
EU (EUVD) id: EUVD-2026-3600
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2026-01-21)
Weakness: CWE-94
Affected product: Cisco Unified Communications Manager
Published: 2026-01-21
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-20045?: 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.
How severe is CVE-2026-20045?: CVE-2026-20045 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-20045 being actively exploited?: Yes. CVE-2026-20045 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-01-21, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-20045?: CVE-2026-20045 primarily affects Cisco Unified Communications Manager. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20045?: 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-2026-20045 have an EU (EUVD) identifier?: Yes. CVE-2026-20045 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3600. It is also flagged as exploited in the EUVD (since 2026-01-21).
When was CVE-2026-20045 published?: CVE-2026-20045 was published on 2026-01-21 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager_im_and_presence_service:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:unity_connection:*:*:*:*:*:*:*:*

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