CVE-2026-58443 in Gitea
Summary
by MITRE • 08/13/2026
Public-only repository tokens can update private PR head branches
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/13/2026
This vulnerability represents a critical access control flaw that allows public repository tokens to manipulate private pull request head branches within the same organization. The technical implementation involves a misconfiguration in the permission model where read-only or public tokens associated with repositories can perform write operations on private branch references, bypassing expected security boundaries. This weakness stems from improper validation of token permissions during branch update operations and demonstrates a failure in implementing least privilege access controls. The vulnerability is particularly concerning because it enables unauthorized modification of private code branches through publicly accessible tokens, creating a potential attack vector for malicious actors to inject malicious code or manipulate repository state without proper authorization.
The operational impact of this vulnerability extends beyond simple code manipulation to encompass complete compromise of private repository integrity and confidentiality. Attackers could leverage this flaw to introduce backdoors, modify sensitive code paths, or create unauthorized commits that persist in the repository history. The vulnerability affects the core Git operations model where branch references are updated through API calls or token-based authentication systems. This issue can be categorized under CWE-284 Access Control Issues and aligns with ATT&CK technique T1578 Resource Hijacking which involves unauthorized modification of resources. The flaw particularly impacts organizations relying on token-based authentication for CI/CD pipelines, automated deployments, and collaborative development environments where public tokens are commonly used for read operations but inadvertently gain write permissions.
Mitigation strategies must focus on implementing granular permission controls that properly separate read and write operations based on token scope and repository visibility. Organizations should enforce strict token management policies that limit the capabilities of public tokens to only those operations necessary for their intended purpose. The recommended approach includes implementing proper access control lists that validate token permissions against target resource visibility levels, ensuring that public tokens cannot modify private branch references regardless of their operational context. Additionally, organizations should establish automated monitoring systems that detect and alert on unauthorized branch modifications, particularly those originating from public tokens. Security measures should also include regular audit trails of all branch update operations to identify potential exploitation attempts. The remediation process requires comprehensive review of authentication mechanisms and implementation of robust permission validation layers that prevent cross-visibility operations between public and private repository resources, aligning with industry best practices outlined in NIST SP 800-53 and ISO/IEC 27001 security controls for access management.