CVE-2026-23634 is a none-severity (CVSS 0) CWE-272 vulnerability in pepr. A fix is available for pepr — see the affected versions and patch details below.
Pepr Overly Permissive RBAC ClusterRole in Admin Mode
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-23634.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
peprnpmDescription
Severity: LOW Target: /workspace/pepr/src/lib/assets/rbac.ts Endpoint: Kubernetes RBAC configuration Method: Deployment
Response / Rationale
Pepr defaults to rbacMode: "admin" because the initial experience is designed to be frictionless for new users. This mode ensures that users can deploy and run the default hello-pepr.ts module without needing to understand or pre-configure RBAC rules.
It’s important to note that hello-pepr.ts is intended strictly as a demo to showcase Pepr features and workflow. It is not intended for production use, and the documentation explicitly calls out that admin RBAC should not be used in production environments.
That said, if a user skips the documentation and does not review the npx pepr build options, they could deploy a module with broader privileges than necessary.
We consider this low severity because Pepr is a framework: the module author is ultimately responsible for selecting the appropriate RBAC scope for their module and environment as each module has different RBAC needs and requirements.
Our security focus is on ensuring the Pepr controller and runtime components operate securely within Kubernetes, while still allowing developers the flexibility to build modules with the access they require.
In order to fix this we will warn the user in logs that the default ClusterRole is cluster-admin and that it is not recommended for production.
How this can be exploited
This is not an inherently exploitable CVE in the traditional sense. It is being flagged because Pepr defaults to a cluster-admin RBAC configuration and does not explicitly force or enforce least-privilege guidance for module authors.
The default behavior exists to make the “getting started” experience smooth: new users can experiment with Pepr and create resources dynamically without needing to pre-configure RBAC.
Remediation: scope RBAC appropriately before deploying to production. Running:
npx pepr build --rbac-mode=scoped
generates the minimum RBAC required for the controller/informer to watch resources. Any additional permissions must be added based on the specific Kubernetes resources and CRUD operations performed by the module
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | pepr | all versions | 1.0.5npm install pepr@1.0.5 |
Affected Products
peprdefenseunicornsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pepr, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pepr to 1.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23634 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.
Frequently Asked Questions
Is CVE-2026-23634 in your dependencies?
Find it across npm, including transitive dependencies.