Medium · published July 24, 2026
A vulnerability in zenml-io/zenml versions 0.57.0 through 0.94.2 allows an attacker to bypass rate-limiting on the `POST /api/v1/login` and self password-change endpoints by rotating the `X-Forwarded-For` header. The rate limiter keys requests by `request.client.host`, which is derived from the `X-Forwarded-For` header when Uvicorn is launched with `--proxy-headers --forwarded-allow-ips *`. This configuration allows clients to control the value of `request.client.host`, effectively bypassing rate-limiting protections. This vulnerability leaves the affected endpoints open to unthrottled credential guessing attacks.