CVE-2026-66877 Gitea fork workflow approval bypass through concurrency cancellation
Attackers can bypass fork workflow approval checks via concurrency cancellation, executing unreviewed code on self-hosted runners.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-66877?
CVE-2026-66877 is a high-severity vulnerability in Gitea, published on 14 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-284
Which versions are affected by CVE-2026-66877?
How do I fix CVE-2026-66877?
No fix has been published for CVE-2026-66877 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-66877 being exploited?
There is no known exploitation of CVE-2026-66877 in the wild and no public exploit code.
Sources
Also known as GHSA-v2w8-m4gr-qj65.