Fission builder pods were created with ServiceAccountName: fission-builder and no AutomountServiceAccountToken: false, so the kubelet auto-mounted the service-account token into every container in the pod — including the
user-supplied builder image.
The user controls the builder container image, command, and podspec through Environment.spec.builder.image / .container / .podspec. With the SA token auto-mounted at /var/run/secrets/kubernetes.io/serviceaccount/token inside that
container, any code running there inherited the fission-builder identity. The fission-builder SA holds namespace-wide get on secrets and configmaps (pkg/utils/serviceaccount.go), so the user-controlled builder container
could read every Secret in the builder namespace by name.
This is the buildermgr sibling of GHSA-85g2-pmrx-r49q (CVE-2026-46617), whose fix suppressed the SA-token automount on function runtime pods but did not cover the structurally identical primitive in pkg/buildermgr/envwatcher.go.
A subject with create/update on Environment CRDs in a namespace observed by the buildermgr could read every Secret and ConfigMap in the builder namespace via the auto-mounted fission-builder token.
Fixed in #3390 and released in v1.24.0. In createBuilderDeployment:
AutomountServiceAccountToken=false on the initial PodSpec and add the projected fetcher SA-token volume.AutomountServiceAccountToken=false after every MergePodSpec call so a user-supplied podspec cannot restore the kubelet automount.Reuses the projected-volume helpers from pkg/executor/util/satoken.go introduced by the GHSA-85g2-pmrx-r49q fix.
The user-supplied builder container no longer receives an auto-mounted SA token. The fetcher sidecar still gets its token via a projected volume.
{
"nvd_published_at": "2026-06-10T18:17:12Z",
"severity": "MODERATE",
"cwe_ids": [
"CWE-250",
"CWE-269",
"CWE-538"
],
"github_reviewed_at": "2026-06-30T18:20:03Z",
"github_reviewed": true
}