CVE-2026-26231: Gitea Permission Bypass Allows Unauthorized Code Commits

Technical summary

CVE-2026-26231 is an authorization bypass vulnerability in Gitea up to version 1.26.1. The flaw resides in how the application evaluates the "Allow edits from maintainers" permission. An authenticated attacker with read access to a repository can manipulate or exploit this permission model to gain unintended write capabilities. The vulnerability is classified under CWE-863 (Incorrect Authorization), indicating a gap between intended and actual access control enforcement. The CVSS 3.1 score of 8.5 reflects the combination of network-based exploitation (AV:N), low complexity (AC:L), low privilege requirements (PR:L), and high integrity impact (I:H), though availability is unaffected.

Business impact

This vulnerability directly threatens code integrity in development workflows. An attacker could inject malicious code, alter commits, or compromise software supply chains without detection if the read-only permission model is trusted as an enforcement boundary. For organizations using Gitea as a central repository, this creates a critical trust gap—developers and auditors may believe certain repositories are protected from modification when they are not. The risk is amplified in CI/CD pipelines that trust repository integrity as a gate for deployment or release decisions.

Affected systems

Gitea versions 1.26.1 and earlier are affected. The vulnerability requires that a user be authenticated and have at least read access to a target repository; repositories with public read access or those shared with read-only team members are at elevated risk. Self-hosted Gitea instances are the primary exposure surface, though the scope of impact depends on repository sharing policies and the sensitivity of repositories involved.

Exploitability

The vulnerability is readily exploitable by any authenticated Gitea user. No special privileges, complex interactions, or user interaction is required beyond standard Git operations. An attacker with read access can perform the malicious action directly, making this a low-friction attack with a low barrier to entry. However, exploitation requires network access to a Gitea instance and valid credentials, preventing completely unauthenticated abuse.

Remediation

Update Gitea to a patched version released after 1.26.1. Verify against the official Gitea security advisory for the exact fixed version number and upgrade timeline. Until patching is possible, review repository permission configurations, especially the use of "Allow edits from maintainers" on sensitive repositories. Consider restricting read access to trusted users or enforcing stricter code review and approval workflows to detect unauthorized commits.

Patch guidance

Apply the latest Gitea release that addresses CVE-2026-26231. Consult the official Gitea project repository or security advisory for the specific version number and installation instructions. Test the patch in a non-production environment first to ensure compatibility with custom configurations or extensions. After upgrade, validate that permission controls function as intended by testing read-only access scenarios.

Detection guidance

Monitor Gitea commit logs and audit trails for commits authored by users with only read-level repository access. Flag any write operations (commits, pushes) originating from accounts lacking explicit write permissions. Implement alerts on Git hook logs for unexpected authorization paths. Review permission audit logs for changes to "Allow edits from maintainers" settings on sensitive repositories. Search for commits made shortly after repository access was granted at the read-only level.

Why prioritize this

This vulnerability rates HIGH due to the combination of high integrity impact, low exploitation complexity, and the foundational role repository integrity plays in software development. The bypass of permission controls is a critical failure in access control design. Organizations should prioritize patching within weeks rather than months, especially if Gitea instances host proprietary code or are integrated into release pipelines.

Risk score, explained

The CVSS 3.1 score of 8.5 reflects a network-accessible vulnerability (AV:N) that requires only low-level authentication (PR:L) with no special conditions or user interaction (AC:L, UI:N). The high integrity impact (I:H)—the ability to modify code without authorization—is the primary driver of severity. The scope change (S:C) indicates that impact extends beyond the vulnerable component to the integrity of dependent systems. Confidentiality impact is low (C:L) and availability is unaffected (A:N), as the attack focuses on unauthorized modification rather than disclosure or denial of service.

Frequently asked questions