The vulnerability (CVE-2026-58424) resides in Gitea Actions' approval gate for workflows triggered by fork pull requests. The function ifNeedApproval incorrectly skips approval if the triggering user has any previously approved workflow run in the repository, regardless of the PR, commit, or workflow file. This logic flaw means that after a single approval by a repository administrator on a benign fork PR, the user is permanently trusted to run arbitrary workflows on the repository's CI infrastructure. The issue was introduced in commit edf98a2dc3 on 2023-02-24 and affects all releases from v1.20.0 through versions prior to 1.26.3, including the latest development builds. No official fix is available yet. The vulnerability requires an authenticated user with fork capability and one-time interaction from a repository admin. It was live-verified on Gitea main branch in May 2026.

An attacker with a standard authenticated account capable of forking the repository can gain persistent ability to execute arbitrary workflow code on the repository's CI runners after a single approval of a benign fork PR workflow by a repository administrator. This allows execution of arbitrary shell commands with network access and repository source access, potentially leading to code execution, data exposure, and disruption of CI infrastructure. The vulnerability undermines the intended security gate for fork PR workflows, effectively granting permanent elevated trust to the attacker within the affected repository.

No official fix or patch is currently available for this vulnerability. Repository administrators should be aware that approving a fork PR workflow run from a new contributor permanently grants that user the ability to run arbitrary workflows without further approval. As a temporary mitigation, administrators should avoid approving fork PR workflow runs from untrusted contributors until a fix is released. Monitor Gitea vendor advisories for updates and apply official patches once available.