CVE-2026-20750: Gitea Auth Bypass Vulnerability

CVE-2026-20750 Overview

Gitea, a self-hosted Git service platform, contains an improper access control vulnerability in its organization project operations. The vulnerability stems from insufficient validation of project ownership during organization-level project operations. A user who has project write access in one organization may be able to modify projects belonging to a different organization, potentially leading to unauthorized data manipulation and cross-organization privilege escalation.

Critical Impact

Authenticated users with project write access in one organization can potentially modify, delete, or alter projects belonging to completely separate organizations, violating intended access boundaries and organizational isolation.

Affected Products

• Gitea versions prior to 1.25.4

Discovery Timeline

• January 22, 2026 - CVE CVE-2026-20750 published to NVD
• January 22, 2026 - Last updated in NVD database

Technical Details for CVE-2026-20750

Vulnerability Analysis

This vulnerability is classified under CWE-284 (Improper Access Control), which occurs when a system does not properly restrict access to resources by unauthorized actors. In this case, Gitea's project management functionality fails to adequately verify that a user performing operations on an organization's project actually has authorization within that specific organization.

The core issue lies in the authorization logic that validates project ownership during modification operations. When a user attempts to modify a project, the system verifies that the user has write access but fails to confirm that the write access applies to the organization that owns the target project. This creates a horizontal privilege escalation scenario where legitimate access in one organization can be leveraged to affect resources in another.

Root Cause

The root cause is an improper access control implementation in Gitea's organization project operations. The validation logic checks for the presence of project write permissions but does not properly scope these permissions to the specific organization context. This allows cross-organization access when a user has write permissions in any organization on the same Gitea instance.

The fix was implemented through pull requests #36318 and #36373, which added proper ownership validation to ensure that project operations are only permitted when the user has appropriate permissions within the target organization.

Attack Vector

An attacker would need to be an authenticated user with project write access in at least one organization on the Gitea instance. With this access, they could craft requests targeting projects in other organizations. The attack does not require any special privileges beyond standard project write access, making it relatively accessible to any authenticated user with organization membership.

The exploitation mechanism involves manipulating API requests or web interface actions to reference project IDs belonging to organizations where the attacker should not have access. Due to the missing ownership validation, these operations would succeed despite crossing organizational boundaries.

Detection Methods for CVE-2026-20750

Indicators of Compromise

• Unexpected modifications to organization projects by users who are not members of that organization
• Audit logs showing project edit or delete operations from users without proper organization membership
• Cross-organization API requests in web server access logs
• Anomalous project configuration changes without corresponding authorized user activity

Detection Strategies

• Review Gitea audit logs for project modification events and cross-reference with organization membership records
• Monitor for API requests to project endpoints where the authenticated user is not a member of the target organization
• Implement alerting on project changes in sensitive organizations and verify the operator's authorization level
• Analyze access patterns for users with multi-organization memberships who access projects outside their primary organizations

Monitoring Recommendations

• Enable comprehensive audit logging in Gitea to capture all project-related operations
• Configure SIEM integration to correlate Gitea authentication events with project modification activities
• Set up alerts for any project deletions or significant modifications in production organizations
• Periodically review organization membership and project access permissions for anomalies

How to Mitigate CVE-2026-20750

Immediate Actions Required

• Upgrade Gitea to version 1.25.4 or later immediately
• Review audit logs for any suspicious cross-organization project modifications
• Temporarily restrict project write access to trusted users until the patch is applied
• Consider implementing additional network-level access controls to limit API access

Patch Information

The vulnerability has been addressed in Gitea version 1.25.4. The patch introduces proper ownership validation in organization project operations to ensure users can only modify projects within organizations where they have legitimate access.

Detailed information about the fix is available in the Gitea Blog Release Notice and the GitHub Release v1.25.4. The security advisory is documented at GitHub Security Advisory GHSA-h4fh-pc4w-8w27.

Workarounds

• If immediate upgrade is not possible, consider restricting organization creation and project write permissions to trusted administrators only
• Implement network segmentation to limit access to the Gitea instance from untrusted networks
• Use a reverse proxy with additional authentication layers to control access to organization-level API endpoints
• Enable strict audit logging and monitor for any cross-organization access patterns

# Upgrade Gitea to patched version
# Stop Gitea service
sudo systemctl stop gitea

# Download and install Gitea 1.25.4 or later
wget https://github.com/go-gitea/gitea/releases/download/v1.25.4/gitea-1.25.4-linux-amd64
chmod +x gitea-1.25.4-linux-amd64
sudo cp gitea-1.25.4-linux-amd64 /usr/local/bin/gitea

# Restart Gitea service
sudo systemctl start gitea

# Verify version
gitea --version