CVE-2026-102478 in Octopus Server
Summary
by MITRE • 10/07/2026
In affected versions of Octopus Server, an authenticated user with permission to modify roles could bypass the protections preventing access abuse resulting in privilege escalation. It was possible for the built-in role to be weakened and the attacker's account added to a privileged team. This was achievable due to improper validation of unsafe equivalence in inputs.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified within affected versions of Octopus Server represents a critical security flaw that allows an authenticated user with specific administrative permissions to escalate their privileges beyond what is intended by the system's access control policies. Specifically, this issue affects users who have been granted permission to modify roles, which should theoretically be limited to adjusting role definitions without altering core system integrity or bypassing existing restrictions. The root cause of this vulnerability lies in improper validation of unsafe equivalence in inputs during the process of modifying user assignments and team memberships. This flaw enables an attacker to manipulate internal data structures by exploiting how the application processes input parameters related to role associations, leading to a breakdown in the enforcement of least privilege principles.
From a technical perspective, the exploitation mechanism involves crafting specific requests that leverage the lack of rigorous validation when updating role configurations. By manipulating these inputs, an authenticated user can weaken the built-in roles that serve as foundational security boundaries within Octopus Server. Once these protective measures are effectively neutralized or altered through this input manipulation, the attacker gains the ability to add their own account to a privileged team. This action circumvents standard authorization checks because the system fails to verify whether such an addition is legitimate given the current state of role permissions and existing security policies. Consequently, the attacker achieves privilege escalation, gaining access to sensitive resources and administrative functions that were previously restricted.
The operational impact of this vulnerability is severe, as it compromises the confidentiality, integrity, and availability of the Octopus Server environment. An adversary who successfully exploits this flaw can assume control over critical infrastructure components managed by Octopus Deploy, potentially leading to unauthorized deployment of code, exfiltration of sensitive configuration data, or disruption of continuous integration and delivery pipelines. This type of privilege escalation undermines trust in the platform's security model and poses significant risks for organizations relying on it for secure software release management. The ability to alter built-in roles also means that future attacks could be facilitated by maintaining persistent access through elevated privileges, making detection and remediation more challenging over time.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-269, which describes Improper Privilege Management, specifically focusing on the failure to enforce proper authorization checks during privilege changes. Furthermore, it maps to MITRE ATT&CK technique T1078, Valid Accounts, as well as T1068 Exploitation for Privilege Escalation, highlighting how legitimate credentials are abused to gain higher-level access. To mitigate this risk, administrators should immediately upgrade Octopus Server to the latest patched version where these input validation checks have been strengthened and equivalence handling has been corrected. Additionally, implementing strict monitoring of role modification events and auditing changes to built-in roles can help detect any unauthorized attempts to exploit this flaw before significant damage occurs. Enforcing multi-factor authentication for administrative accounts further reduces the likelihood that an attacker can successfully leverage stolen or compromised credentials to execute such attacks.