GHSA-m63v-2g9w-2w6v is a critical-severity (CVSS 9.9) CWE-250 vulnerability in github.com/fission/fission. O3 Security confirms whether GHSA-m63v-2g9w-2w6v is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation
Real-World Exposure
github.com/fission/fissionReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A follow-up bypass of the round-4 PodSpec hardening (GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92). Those advisories validate and sanitize the PodSpec (spec.runtime.podSpec / spec.builder.podSpec /
function.spec.podSpec), but the Environment CRD also exposes spec.runtime.container and spec.builder.container — a standalone Container merged into the runtime/builder pod whose SecurityContext bypassed both layers.
Details
Admission-layer gap. Environment.Validate() calls ValidatePodSpecSafety() on Runtime.PodSpec and Builder.PodSpec only. That function takes a *PodSpec, so it never inspects the standalone Runtime.Container.SecurityContext
or Builder.Container.SecurityContext.
Merge-layer gap. sanitizeContainerSecurityContext() ran only inside MergePodSpec(). The container field is merged via MergeContainer(), which did not sanitize. With only Runtime.Container set and Runtime.PodSpec nil,
MergePodSpec is never invoked, so the sanitizer never ran.
Affected merge sites: poolmgr (gp_deployment.go), newdeploy (newdeploy.go), and buildermgr (envwatcher.go).
Proof of concept
apiVersion: fission.io/v1
kind: Environment
metadata:
name: priv-escape-test
namespace: default
spec:
version: 3
runtime:
image: "ghcr.io/fission/python-env:latest"
container:
name: priv-escape-test
securityContext:
privileged: true
poolsize: 1
The admission webhook accepts this Environment and the resulting pool pod runs with privileged: true. Equivalent bypasses: allowPrivilegeEscalation: true, capabilities.add: ["SYS_ADMIN"], capabilities.add: ["NET_ADMIN","SYS_PTRACE"]. The same attack applies to Builder.Container.
Impact
A tenant with environments.fission.io create/update RBAC can run privileged / allowPrivilegeEscalation / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor's high-privilege
service account — enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. Identical blast radius to GHSA-gx55-f84r-v3r7.
Fix
Fixed in #3406 and released in v1.24.0.
- Admission layer (primary defence): a new
ValidateContainerSafetyinpkg/apis/core/v1/podspec_safety.goapplies the per-container SecurityContext denylist (privileged,allowPrivilegeEscalation, dangerous capabilities) to a standalone container, and is called fromEnvironment.Validate()forRuntime.ContainerandBuilder.Container. - Merge layer (defence in depth):
sanitizeContainerSecurityContext()is now invoked insideMergeContainer()itself, covering all three executor/builder call sites.
Workarounds
- Restrict Environment create/update RBAC to trusted administrators.
- Deploy a Kyverno / OPA Gatekeeper policy rejecting dangerous Container SecurityContext on Environment CRDs.
- Label the function/builder namespaces with
pod-security.kubernetes.io/enforce: restricted.
References
- GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92 — the round-4 PodSpec fixes this advisory bypasses (#3391,
e484df84).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/fission/fission | all versions | 1.24.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fission/fission. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/fission/fission to 1.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m63v-2g9w-2w6v is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-m63v-2g9w-2w6v is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-m63v-2g9w-2w6v. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-m63v-2g9w-2w6v in your dependencies?
O3 detects GHSA-m63v-2g9w-2w6v across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.