Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.24.0, Fission's Container Executor path lets a tenant supply Function.spec.podspec directly; the executor merges it into the executor-built podspec and creates a Deployment whose pods run the user's container image. This issue has been patched in version 1.24.0.

Affected: Go: github.com/fission/fission

### Summary

Fission's Container Executor path lets a tenant supply `Function.spec.podspec` directly; the executor merges it into the executor-built podspec and creates a Deployment whose pods run the user's container image.

### Details

Two flaws compounded:

1. `pkg/apis/core/v1/validation.go::FunctionSpec.Validate` only checked that `spec.PodSpec != nil` when `executorType: container`; it did not inspect the content of `spec.PodSpec`. 2. `pkg/executor/util/merge.go::MergePodSpec` unconditionally forwarded `hostPID`, `hostNetwork`, `hostIPC`, hostPath volumes, `serviceAccountName`, and container `privileged` into the Deployment spec via the container-executor sink (`pkg/executor/executortype/container/deployment.go::getDeploymentSpec`).

A tenant with only `functions.fission.io/create` could deploy a Function with a crafted podspec that mounted the host root filesystem and shared host namespaces. The executor — running under its high-privilege SA, which holds `deployments/create` on the function namespace — created that Deployment on the tenant's behalf, turning Function-create into effective `deployments/create` with arbitrary pod-security configuration.

This is the Function-CRD sibling of GHSA-gx55-f84r-v3r7 / GHSA-wmgg-3p4h-48x7, with a **lower** attack threshold: regular function developers typically hold `functions/create` but not `environments/create`.

### Impact

A tenant with only `functions.fission.io/create` is escalated to node escape via a privileged, host-n…