CVE-2026-27783 in Gitea
Summary
by MITRE • 07/04/2026
Gitea versions up to and including 1.26.1 do not enforce repository-unit authorization on issue-template API endpoints.
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Analysis
by VulDB Data Team • 07/04/2026
The vulnerability in Gitea versions up to and including 1.26.1 represents a critical authorization bypass flaw that undermines the security model of the platform's repository management capabilities. This issue affects the issue-template API endpoints where the application fails to properly validate user permissions before allowing access to repository-specific template configurations. The flaw exists within the core authentication and authorization framework, specifically in how the system handles repository unit access controls for issue templates. According to CWE-285, this constitutes an improper authorization vulnerability where authenticated users can potentially access or modify repository templates without possessing the necessary privileges. The affected endpoints likely include operations related to creating, reading, updating, and deleting issue templates within repositories, which are fundamental components of project management and issue tracking workflows.
The technical implementation of this vulnerability stems from inadequate access control checks within the API layer that processes repository unit requests. When users make requests to the issue-template endpoints, the system should verify that the requesting user has appropriate permissions to modify or access the target repository's issue templates. However, in affected versions, these authorization checks are either missing entirely or implemented incorrectly, allowing unauthorized access to template configurations that should be restricted based on repository membership, role assignments, or permission levels. This flaw can be exploited by malicious actors who have gained access to the platform through other means or by individuals with lower privilege levels attempting to escalate their access within repository boundaries.
The operational impact of this vulnerability extends beyond simple data exposure and could enable significant security risks within organizations relying on Gitea for code repository management. Attackers could potentially modify issue templates to include malicious content, redirect users to phishing sites, or create misleading workflows that could compromise project integrity. The consequences are particularly severe in enterprise environments where repositories may contain sensitive project information, development workflows, or compliance-related configurations. An attacker with access to a single repository could potentially manipulate templates across multiple projects if the authorization mechanism is consistently bypassed throughout the platform's API endpoints. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation through improper access control mechanisms.
Organizations using affected Gitea versions should immediately implement mitigations including upgrading to version 1.26.2 or later where this authorization bypass has been patched. Additionally, administrators should review existing repository permissions and access controls to ensure that unauthorized modifications have not occurred. The patch for this vulnerability typically involves strengthening the API endpoint authorization checks to properly validate user permissions against repository units before allowing template operations. Security teams should also conduct comprehensive audits of repository templates across all projects to identify any unauthorized changes that may have occurred during the vulnerable period. Monitoring logs for unusual activity around issue-template endpoints can help detect exploitation attempts and provide evidence for forensic analysis. Organizations relying on Gitea should consider implementing additional security controls such as API rate limiting and enhanced logging to prevent abuse of the affected endpoints while awaiting full patch deployment across all instances.