VulnerabilityPublished 4 Jun 2025Updated 26 Feb 2026

CVE-2025-20261: Cisco Unified Computing System (Managed) · Improper Restriction of Communication Channel to Intended Endpoints

Affects Cisco Unified Computing System (Managed)Source CVE Database V5

Not known to be exploited · CVSS 8.8 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

8.8High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2025-20261, organizations should: 1) Immediately identify and inventory all Cisco UCS systems running affected IMC versions. 2) Apply Cisco’s official patches or firmware updates as soon as they become available to address the vulnerability. 3) Restrict SSH access to Cisco IMC interfaces using network segmentation, firewall rules, and access control lists to limit exposure to trusted administrative hosts only. 4) Enforce strong authentication mechanisms, including multi-factor authentication (MFA), to reduce risk from compromised credentials. 5) Regularly audit user accounts and privileges on UCS systems to detect and remove unauthorized or unnecessary accounts. 6) Monitor SSH logs and IMC access logs for unusual or suspicious activity indicative of exploitation attempts. 7) Consider implementing jump servers or bastion hosts for administrative access to further control and monitor connections. 8) Educate administrators on secure credential handling and the importance of timely patching. 9) Develop and test incident response plans specific to UCS infrastructure compromise scenarios. These steps go beyond generic advice by focusing on access restriction, credential hygiene, and proactive monitoring tailored to the UCS environment.

Description

A vulnerability in the SSH connection handling of Cisco Integrated Management Controller (IMC) for Cisco UCS B-Series, UCS C-Series, UCS S-Series, and UCS X-Series Servers could allow an authenticated, remote attacker to access internal services with elevated privileges. This vulnerability is due to insufficient restrictions on access to internal services. An attacker with a valid user account could exploit this vulnerability by using crafted syntax when connecting to the Cisco IMC of an affected device through SSH. A successful exploit could allow the attacker to access internal services with elevated privileges, which may allow unauthorized modifications to the system, including the possibility of creating new administrator accounts on the affected device.

Impact

The potential impact of CVE-2025-20261 is severe for organizations using affected Cisco UCS servers. An attacker with valid credentials can escalate privileges to administrator level, enabling unauthorized system modifications, including creation of new admin accounts. This can lead to full control over the affected UCS management infrastructure, compromising the confidentiality, integrity, and availability of the server environment. Such control can facilitate further lateral movement within enterprise networks, data exfiltration, disruption of critical services, and persistent backdoors. Given the central role of Cisco UCS in data centers and enterprise IT infrastructure, exploitation could disrupt business operations, damage reputation, and cause significant financial losses. The vulnerability’s network accessibility and lack of user interaction requirement increase the risk of exploitation. Organizations in sectors such as finance, healthcare, government, telecommunications, and cloud service providers are particularly vulnerable due to their reliance on Cisco UCS for critical workloads and infrastructure management.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucs-ssh-priv-esc-2mZDtdjM (opens in a new tab)

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 26 Feb 2026, 20:42 UTC

Technical details

References

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