CVE-2025-0326 in Carbon OAuth
Summary
by MITRE • 10/22/2026
The system fails to invalidate existing access tokens associated with sub-organization users during sensitive account management operations such as password reset, role change, or sub-organization disablement. This oversight allows previously issued tokens to remain active even after the user's access context has been modified or revoked through administrative actions.
The identified issue could lead to unauthorized access by a malicious actor, but only when all of the following conditions are met: previously issued access tokens remain active, and these tokens have been exposed to malicious actors.
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Analysis
by VulDB Data Team • 10/22/2026
This vulnerability represents a critical failure in session management and token lifecycle control within multi-tenant or hierarchical organizational structures. The core technical flaw lies in the system's inability to propagate invalidation signals from high-level administrative actions down to existing active sessions for sub-organization users. When an administrator performs sensitive operations such as resetting a user password, changing their role permissions, or disabling access to a specific sub-organization, the backend logic fails to revoke or blacklist the corresponding JSON Web Tokens (JWT) or session identifiers that were previously issued and distributed to the client side. Consequently, these tokens retain their cryptographic validity and are accepted by the authentication middleware as legitimate credentials, despite the underlying user state having been fundamentally altered or revoked. This creates a persistent security gap where the system's authorization decisions based on current database states conflict with its access control enforcement mechanisms that rely solely on token signature verification without checking for recent revocation status.
The operational impact of this flaw is significant in environments requiring strict adherence to least-privilege principles and rapid incident response capabilities. If an attacker has obtained a valid access token through network sniffing, cross-site scripting attacks, or insecure storage practices, they can continue to exploit that token indefinitely until its natural expiration time elapses, regardless of whether the legitimate user's password was changed or their account was disabled by administrators. This undermines the effectiveness of standard incident response procedures such as immediate account suspension during a breach investigation. For example, if an employee leaves an organization and is immediately deactivated, any tokens they previously acquired remain functional, allowing for potential data exfiltration or unauthorized modifications that bypass intended access controls. The severity is further amplified in sub-organization contexts where trust boundaries are complex; attackers could potentially pivot between different organizational units using stale credentials to access resources outside their authorized scope.
From a classification perspective, this issue aligns with CWE-613, which describes insufficient session expiration, and more specifically relates to the broader category of CWE-284 Improper Access Control where authorization decisions are not consistently enforced against all active sessions. In terms of the MITRE ATT&CK framework, this vulnerability facilitates Initial Access via Valid Accounts (T1078) and can be leveraged for Persistence if attackers maintain long-lived tokens to retain access after detection attempts fail. It also intersects with CWE-384 Session Fixation concepts in that existing valid sessions are not invalidated upon security-relevant state changes. The risk is contingent on the attacker's ability to acquire a token, but once acquired, the lack of revocation mechanisms provides an extended window of opportunity for exploitation compared to systems that implement immediate session invalidation policies.
To mitigate this vulnerability, developers must implement robust server-side token blacklisting or short-lived access tokens paired with refresh token rotation strategies. When sensitive account management operations occur, such as password resets or role changes, the system should immediately add the affected user's active token identifiers to a centralized revocation list stored in a fast-access database like Redis. Alternatively, implementing stateless JWTs with embedded version numbers or last-password-change timestamps allows the server to validate tokens against current user attributes without requiring external storage lookups for every request. Additionally, adopting short expiration times for access tokens reduces the window of opportunity for attackers using stolen credentials. Security teams should also enforce strict token binding mechanisms and ensure that all administrative actions trigger immediate session invalidation across all devices associated with the affected account to maintain consistent security posture during critical state transitions.