GHSA-cvw6-gfvv-953q is a high-severity (CVSS 8.5) CWE-284 vulnerability in github.com/fission/fission. O3 Security confirms whether GHSA-cvw6-gfvv-953q is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Fission: Cross-namespace Environment reference via unvalidated EnvironmentRef in Function admission webhook
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
The Fission Function admission webhook (pkg/webhook/function.go) validated that spec.secrets[].namespace and spec.configmaps[].namespace equalled the function's own namespace but performed no equivalent check on
spec.environment.namespace.
Details
An attacker with permission to create Functions in their own namespace could set spec.environment.namespace to any other tenant's namespace. poolmgr and newdeploy would then look up and use the victim's Environment CRD when scheduling
function pods, so the attacker's function executed inside the victim's container image.
This is useful both for code and credential theft — the victim's runtime image may contain hardcoded secrets — and for confused-deputy attacks where the victim's runtime image is a privileged sidecar.
Impact
A tenant with functions.fission.io/create could run their own function code inside another tenant's container image, breaking the namespace trust boundary that the Function specification implies.
Fix
Fixed in #3389 and released in v1.24.0.
- Admission webhook (
pkg/webhook/function.go::Validate) rejectsFunction.spec.environment.namespace != metadata.namespace. An empty namespace remains accepted (the CLI defaults it to the function's namespace). - Controller belt-and-braces: the same check runs before the cross-namespace
Environments(...).Getin poolmgrgetFunctionEnvand newdeployfnCreate/RefreshFuncPods, covering webhook-bypass clusters (failurePolicy=Ignore) and stale Function objects from upgrade-before-restart windows.
Behavioural change
Functions that explicitly set spec.environment.namespace to a different namespace are now rejected at admission. Empty-string remains accepted.
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-cvw6-gfvv-953q 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-cvw6-gfvv-953q 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-cvw6-gfvv-953q. 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-cvw6-gfvv-953q in your dependencies?
O3 detects GHSA-cvw6-gfvv-953q across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.