{"id":"CVE-2026-66877","summary":"Gitea fork workflow approval bypass through concurrency cancellation","details":"Gitea enforces first-time fork contributor approval by blocking jobs, but some job transition and dispatch paths do not re-check the run's approval requirement. A separate run sharing a job-level concurrency group can cancel a pending job and cause its blocked sibling jobs to be re-emitted and dispatched without approval. This allows unreviewed workflow code to execute on self-hosted runners; fork secrets remain withheld and the run token remains read-only.","aliases":["GHSA-v2w8-m4gr-qj65"],"modified":"2026-10-16T02:48:06.241530440Z","published":"2026-10-14T14:36:11.356Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66877.json","cna_assigner":"Gitea"},"references":[{"type":"ADVISORY","url":"https://blog.gitea.com/release-of-1.27.3/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66877.json"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/releases/tag/v1.27.3"},{"type":"ADVISORY","url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-v2w8-m4gr-qj65"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66877"},{"type":"FIX","url":"https://github.com/go-gitea/gitea/pull/39005"},{"type":"FIX","url":"https://github.com/go-gitea/gitea/pull/39018"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/go-gitea/gitea","events":[{"introduced":"0"},{"fixed":"146cc3eec57174711eac0e0a0c7b38670c6e3922"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"last_affected":"1.27.2"}]}}],"versions":["v1.27.2","v1.27.1","v1.27.0","v1.27.0-rc0","v1.28.0-dev","v1.27.0-dev","v1.26.0-dev","v1.25.0-dev","v1.24.0-dev","v1.22.0-rc1","v1.23.0-dev","v1.22.0-rc0","v1.21.0-rc0","v1.22.0-dev","v1.20.0-rc0","v1.21.0-dev","v1.20.0-dev","v1.19.0-rc0","v1.18.0-rc0","v1.19.0-dev","v1.18.0-dev","v1.17.0-dev","v1.16.0-rc1","v1.15.0-rc1","v1.16.0-dev","v1.15.0-dev","v1.14.0-dev","v1.13.0-dev","v1.12.0-dev","v1.10.5","v1.11.0-rc1","v1.10.0-rc1","v1.11.0-dev","v1.9.0-rc1","v1.10.0-dev","v1.9.0-dev","v1.7.0-dev","v1.6.0-rc1","v1.6.0-dev","v1.5.0-rc1","v1.5.0-dev","v1.1.0","v1.0.0","v0.9.99"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66877.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}