cvedb.io
CVE-2026-40109
LOW · CVSS 3.1
EPSS exploitation probability: 0%
Published 2026-04-09T21:16:12.277 · Last modified 2026-06-17T10:44:44.253

Summary

Flux notification-controller is the event forwarder and notification dispatcher for the GitOps Toolkit controllers. Prior to 1.8.3, the gcr Receiver type in Flux notification-controller does not validate the email claim of Google OIDC tokens used for Pub/Sub push authentication. This allows any valid Google-issued token, to authenticate against the Receiver webhook endpoint, triggering unauthorized Flux reconciliations. Exploitation requires the attacker to know the Receiver's webhook URL. The webhook path is generated as /hook/sha256sum(token+name+namespace), where the token is a random string stored in a Kubernetes Secret. There is no API or endpoint that enumerates webhook URLs. An attacker cannot discover the path without either having access to the cluster and permissions to read the

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.