CVE-2026-17600 in Nexus Repository
Summary
by MITRE • 08/07/2026
Sonatype Nexus Repository 3 did not immediately terminate a user's active login session or revoke their cached permissions when that user's account was deleted, deactivated, or had its password changed. A user whose account was already logged in at the time of one of these actions could continue using their existing session to interact with the repository as though the account were still active, until that session independently expired. Depending on the permissions previously held, this could allow continued unauthorized access to read, modify, or delete repository content after access was intended to be revoked.
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Analysis
by VulDB Data Team • 08/07/2026
This vulnerability represents a critical session management flaw in Sonatype Nexus Repository 3 that directly violates fundamental security principles of access control and authentication lifecycle management. The issue stems from inadequate session invalidation mechanisms where the system fails to properly terminate active user sessions or revoke cached permissions when account modifications occur. This represents a classic case of insufficient session handling as classified under CWE-613, where the system does not adequately manage session lifecycles following account state changes. The vulnerability exists in the authentication and authorization subsystem, specifically in how the repository handles user account lifecycle events such as deletion, deactivation, or password changes, which should trigger immediate session termination across all active connections.
The operational impact of this vulnerability extends far beyond simple access control bypasses, creating potential for significant data compromise within repository environments. When a user account is deleted or deactivated, legitimate administrators may expect immediate revocation of all associated privileges and access rights, yet the system continues to honor existing sessions until natural expiration occurs. This creates an extended window of opportunity for unauthorized access that can persist for hours or days depending on session timeout configurations. The vulnerability particularly affects scenarios where sensitive repository content is stored, including proprietary code, configuration files, and artifacts that may contain intellectual property or security-sensitive information. Attackers could exploit this weakness by gaining initial access through legitimate means and then leveraging the extended session window to maintain persistence even after account removal, effectively circumventing intended access controls.
The technical implementation flaw manifests in the repository's failure to properly coordinate between authentication state changes and active session management. When an account undergoes modification such as password reset or deactivation, the system should immediately invalidate all associated session tokens and clear cached permissions from memory. This process should be atomic and immediate, ensuring that no stale privileges remain accessible through existing connections. The absence of this mechanism creates a privilege escalation path where users can continue performing actions they would not normally be authorized to execute, potentially leading to data modification or deletion. This vulnerability aligns with ATT&CK technique T1563.002 - "Access Token Manipulation" in that it allows continued use of compromised session tokens despite account state changes, and also relates to T1078 - "Valid Accounts" as it exploits legitimate user sessions that have not been properly terminated.
Security controls and mitigations for this vulnerability require immediate attention through both software patches and operational procedures. Organizations should implement immediate remediation by applying the latest security updates from Sonatype that address session invalidation mechanisms. Additionally, system administrators should configure shorter session timeouts to minimize the window of opportunity for exploitation, while implementing comprehensive monitoring for account modification events and corresponding session invalidation activities. The solution must ensure proper synchronization between account state changes and session termination processes, with logging capabilities to track when sessions are invalidated due to account modifications. Network segmentation and additional access controls should be implemented as compensating measures until full patch deployment occurs. This vulnerability highlights the importance of implementing robust session management protocols that align with industry standards such as those recommended in NIST SP 800-63B for authentication and session handling, ensuring that account lifecycle events properly propagate through all security layers within the system architecture.