CVE-2026-54495
MEDIUMCVE-2026-54495 is a medium-severity (CVSS 4.3) vulnerability in github.com/open-feature/open-feature-operator. O3 Security confirms whether CVE-2026-54495 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
open-feature-operator: Cross-namespace FeatureFlagSource and InProcessConfiguration resolution exposes spec contents on multi-tenant clusters
Real-World Exposure
github.com/open-feature/open-feature-operatorReal-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 namespaced FeatureFlagSource or InProcessConfiguration resource can be referenced cross-namespace via the openfeature.dev/featureflagsource annotation using the documented {NAMESPACE}/{NAME} syntax. The operator resolves the referenced resource cluster-wide and materializes its contents (env vars, flagd sidecar arguments including httpSyncBearerToken, sync URIs, supporting ConfigMaps) into the referencing workload.
On multi-tenant clusters that treat namespaces as trust boundaries, a tenant who can deploy a controller-owned workload in their own namespace can cause the operator to read another tenant's FeatureFlagSource / InProcessConfiguration spec contents.
Impact
- Single-tenant clusters: not impacted.
- Multi-tenant clusters using namespaces as trust boundaries: tenant-to-tenant disclosure of any data placed inline in
FeatureFlagSource/InProcessConfigurationspec, includingspec.envVarsliteral values,spec.httpSyncBearerToken, and sync URIs.
Behavior is documented
The cross-namespace {NAMESPACE}/{NAME} annotation syntax is intentional and documented in docs/annotations.md and docs/feature_flag_source.md. The operator's cluster-wide RBAC scope is intentional. Namespace-as-trust-boundary is not part of the operator's current stated security model.
This advisory makes the tenancy assumption explicit and tracks the architectural change that will eliminate the implicit cross-namespace pattern.
Corrections to the original report
Two technical points in the original report require correction:
secretKeyRef/configMapKeyRefcross-namespace disclosure is not possible via this path. Kubelet resolves these asLocalObjectReferenceagainst the pod's own namespace; the operator does not bypass that. The actual disclosure surface isFeatureFlagSource/InProcessConfigurationspec contents the operator itself materializes (inlineenvVarsvalues,httpSyncBearerToken, sync URIs).create featureflagsourcesis not a prerequisite. The webhook rejects pods without OwnerReferences (pod_webhook.go:75-77), so the prerequisite iscreateon a workload controller (deployments,statefulsets,daemonsets,jobs,cronjobs,replicasets) in a namespace the attacker controls.FeatureFlagSourcecreate in any namespace is not required.
Mitigations
As with any Kubernetes CRD, treat the spec content of FeatureFlagSource and InProcessConfiguration as readable by anyone with read access to the resource, and don't place plaintext secrets in CR spec fields. Fields most likely to bite users:
spec.sources[].source, when the URI embeds credentials (e.g.https://user:pass@host/repo)spec.sources[].certPath, if the path itself is sensitive- inline
spec.envVars[].value(usevalueFrom.secretKeyRefinstead; kubelet enforces same-namespace resolution and the secret value is not stored in the CR)
If developers treat namespaces as trust boundaries:
- restrict
createonfeatureflagsources/inprocessconfigurationsvia RBAC where feasible,
Roadmap
A future release will introduce explicit cluster-scoped CRDs (ClusterFeatureFlagSource, ClusterInProcessConfiguration) and remove implicit cross-namespace resolution. This is a breaking change tracked in #847.
Precedent
This class of issue (authenticated namespace tenant abuses an unenforced cluster-wide surface that crosses an assumed namespace boundary) has Kubernetes precedent: CVE-2020-8554 (External IPs) was accepted as documented posture and mitigated via an opt-in admission plugin.
Credit
Reported by @0xVijay. Thanks for the disclosure. This appears to be an example of https://cwe.mitre.org/data/definitions/668.html. In terms of how it ended up here, it's more of an unimplemented security feature than an "bug". It seems to deviate from reasonable expectations and conventions in the K8s ecosystem. See https://nvd.nist.gov/vuln/detail/cve-2020-8554 as an example of a comparable vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/open-feature/open-feature-operator | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/open-feature/open-feature-operator. 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.
Remediation status
No patched version of github.com/open-feature/open-feature-operator has shipped for CVE-2026-54495 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 CVE-2026-54495 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 CVE-2026-54495. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-54495 in your dependencies?
O3 detects CVE-2026-54495 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.