Fission: HTTPTrigger admission omits RelativeURL / Prefix validation; kubectl apply bypasses CLI checks

CVE-2026-50569

What is CVE-2026-50569?

Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.25.0, HTTPTriggerSpec.Validate() validated Methods, FunctionReference, Host, IngressConfig, and CorsConfig, but silently skipped RelativeURL and Prefix. Those two fields were validated at the CLI level only (pkg/fission-cli/cmd/httptrigger/create.go:83). The post-CRD-modernization webhook for HTTPTrigger was retired in favor of API-server CEL — and CEL had no rules on those fields either — so an HTTPTrigger created via kubectl apply or a direct Kubernetes REST API call bypassed every URL-level check. This issue has been patched in version 1.25.0.

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