The vulnerability arises from prototype pollution in the Trigger.dev run‑metadata endpoint. By supplying attacker‑controlled operation.key values that include dangerous constructor and prototype path segments, a caller with a normal environment API key can set properties on Object.prototype. This corrupts internal Prisma queries, Prometheus labels, and worker authentication, ultimately causing a process‑wide denial of service that spans all tenants. The underlying weakness is classified as CWE‑1321.

The Trigger.dev platform is affected, specifically the API endpoint /api/v1/runs/:runId/metadata. All releases from 3.3.8 up to and including 4.5.6 contain the flaw; versions beyond 4.5.6 are not impacted.

With a CVSS score of 8.5 the issue is considered high severity. The EPSS score is not available, but exploitation requires only a legitimate environment API key and the ability to send an HTTP PUT request, making the attack vector likely remote and straightforward. Although it is not listed in the CISA KEV catalog, the potential for cross‑tenant disruption and the process‑wide impact warrant prompt attention.