CVE-2025-71435 in Coder
Summary
by MITRE • 10/17/2026
Coder before 2.23.0 contains a session expiration bypass vulnerability that allows authenticated users to retain access after OIDC token expiry when no refresh token is issued. Users can keep their APIKey cookie active through regular use, extending it every 24 hours to access Coder indefinitely after losing OIDC authorization.
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Analysis
by VulDB Data Team • 10/17/2026
The vulnerability identified in versions of the Coder platform prior to release 2.23.0 represents a critical authentication bypass flaw rooted in the improper handling of session lifecycle management when integrating with OpenID Connect providers. This issue specifically affects environments where the application relies on OIDC for initial user authorization but maintains persistent access through local API key mechanisms. The core technical deficiency lies in the logic that governs the expiration and renewal of the APIKey cookie, which serves as a secondary authentication token within the Coder ecosystem. When an authenticated user interacts with the platform, the system is designed to refresh this session token periodically to maintain continuity of service. However, the implementation fails to adequately validate whether the underlying OIDC authorization remains valid before extending the local session's lifespan.
In a secure architecture, the persistence of any secondary authentication mechanism should be strictly coupled with the validity of the primary identity provider credentials. In this flawed implementation, if an organization configures Coder to use OIDC for login but does not issue refresh tokens or relies on short-lived access tokens without proper backend validation during session renewal, the application incorrectly assumes that continued user activity implies ongoing authorization. Consequently, as long as a user actively uses the platform within specific intervals, typically every twenty-four hours, the system automatically extends the validity of their APIKey cookie. This behavior creates a persistent state where the local authentication token remains valid regardless of changes in the external identity provider's status regarding that user.
The operational impact of this vulnerability is severe for organizations relying on centralized access control through OIDC providers such as Okta, Azure AD, or Google Workspace. If an administrator revokes a user's account in the identity provider to terminate their employment or remove unauthorized access, the affected Coder instance does not immediately recognize this change. Instead, it continues to accept requests authenticated by the stale APIKey cookie until that specific token expires naturally through normal usage patterns. This allows former employees or malicious actors who have obtained valid credentials before revocation to retain indefinite access to sensitive code repositories, development environments, and associated infrastructure resources. The bypass effectively negates the immediate security controls intended by identity provider account termination procedures.
This vulnerability aligns with CWE-613, which describes insufficient session expiration, as well as aspects of CWE-287 involving improper authentication checks during state transitions. From a threat modeling perspective using the MITRE ATT&CK framework, this flaw facilitates Account Manipulation and Persistence techniques by allowing an adversary to maintain foothold in a system after initial credentials have been compromised or revoked at the identity layer. The attack vector is particularly dangerous because it does not require exploiting a traditional buffer overflow or injection flaw; rather, it exploits logical misconfiguration within the session management workflow that persists across standard user interactions.
To mitigate this risk, organizations running Coder versions prior to 2.23.0 must upgrade immediately to version 2.23.0 or later where these logic flaws have been addressed. The patch ensures that session renewal processes strictly validate the current status of the OIDC token against the identity provider before extending local session cookies. Additionally, administrators should review their OIDC configurations to ensure robust refresh token policies are in place if supported by their identity provider, although reliance on such tokens alone is insufficient without proper backend validation during every API request or session renewal event. Implementing short-lived access tokens combined with rigorous server-side verification of user status at each interaction point provides the necessary defense-in-depth strategy to prevent unauthorized persistence within the application layer.