How severe is CVE-2025-20309?

CVE-2025-20309 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-20309 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-20309?

CVE-2025-20309 primarily affects Cisco Unified Communications Manager. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-20309?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-20309 have an EU (EUVD) identifier?

Yes. CVE-2025-20309 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-19749.

When was CVE-2025-20309 published?

CVE-2025-20309 was published on 2025-07-02 and last updated on 2026-06-17.

CVE-2025-20309

CVE-2025-20309 is a critical-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-798.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-19749
Weakness: CWE-798
Affected product: Cisco Unified Communications Manager
Published: 2025-07-02
Last modified: 2026-06-17

Description

A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to log in to an affected device using the root account, which has default, static credentials that cannot be changed or deleted. This vulnerability is due to the presence of static user credentials for the root account that are reserved for use during development. An attacker could exploit this vulnerability by using the account to log in to an affected system. A successful exploit could allow the attacker to log in to the affected system and execute arbitrary commands as the root user.

Frequently asked questions

What is CVE-2025-20309?: A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to log in to an affected device using the root account, which has default, static credentials that cannot be changed or deleted. This vulnerability is due to the presence of static user credentials for the root account that are reserved for use during development. An attacker could exploit this vulnerability by using the account to log in to an affected system. A successful exploit could allow the attacker to log in to the affected system and execute arbitrary commands as the root user.
How severe is CVE-2025-20309?: CVE-2025-20309 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-20309 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-20309?: CVE-2025-20309 primarily affects Cisco Unified Communications Manager. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-20309?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-20309 have an EU (EUVD) identifier?: Yes. CVE-2025-20309 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-19749.
When was CVE-2025-20309 published?: CVE-2025-20309 was published on 2025-07-02 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-ssh-m4UBdpE7

Affected products (16)

cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13010-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13010-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13011-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13011-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13012-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13012-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13013-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13013-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13014-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13014-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13015-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13015-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13016-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13016-1:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13017-1:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:15.0.1.13017-1:*:*:*:session_management:*:*:*

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