CVE-2026-52804 in Gogs
Summary
by MITRE • 06/25/2026
Gogs is an open source self-hosted Git service. Prior to 0.14.3, a repository admin collaborator can escalate their privileges to owner-level access by exploiting an off-by-one error in the ChangeCollaborationAccessMode function. This vulnerability is fixed in 0.14.3.
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Analysis
by VulDB Data Team • 06/25/2026
The Gogs Git service vulnerability represents a critical privilege escalation issue that undermines the security model of collaborative repository management. This flaw affects versions prior to 0.14.3 and specifically targets the access control mechanisms that govern repository collaboration permissions. The vulnerability stems from an off-by-one error within the ChangeCollaborationAccessMode function, which is responsible for managing the transition of user permissions between different collaboration levels. Such errors typically occur when boundary conditions are not properly handled in programming logic, creating opportunities for unauthorized access that bypass intended security controls.
The technical implementation of this vulnerability exploits a fundamental flaw in input validation and permission handling within the repository management system. When an admin collaborator attempts to modify access modes for other users, the off-by-one error allows them to manipulate the underlying data structures in a way that grants elevated privileges beyond their original authorization level. This type of vulnerability falls under the CWE-129 category of Improper Validation of Array Index, which specifically addresses issues where array indices are not properly validated against their bounds. The flaw essentially creates a condition where the system fails to correctly enforce access control boundaries, enabling unauthorized privilege elevation through malformed input or manipulation of permission states.
The operational impact of this vulnerability extends beyond simple security implications to potentially compromise entire repository ecosystems and the data they contain. An attacker with admin collaborator privileges can exploit this weakness to gain full owner-level access, which typically includes the ability to delete repositories, modify system configurations, add or remove other collaborators, and potentially access sensitive information that should remain restricted. This privilege escalation directly violates the principle of least privilege that forms the foundation of secure multi-user systems. The vulnerability affects not only individual repositories but could potentially allow attackers to compromise entire Gogs instances by escalating their privileges across multiple repository boundaries.
Mitigation strategies for this vulnerability require immediate implementation of the patched version 0.14.3 or later, which addresses the underlying off-by-one error in the access control validation logic. Organizations should conduct comprehensive security audits of their Gogs installations to identify and remediate any potential exploitation attempts before patching. The fix likely involves proper bounds checking in the ChangeCollaborationAccessMode function to ensure that all access mode transitions are validated against legitimate permission levels and that no unauthorized privilege escalation paths exist. Additionally, organizations should implement monitoring for suspicious permission changes and establish regular security assessments of their collaboration management systems. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting local privilege escalation through access control manipulation. Security teams should also consider implementing network segmentation and access controls around Git service endpoints to limit potential exploitation vectors while awaiting patch deployment.