kyverno-policy-review

name	kyverno-policy-review
description	Use this skill for Kyverno policy review across the stable policies.kyverno.io/v1 API surface — ValidatingPolicy, MutatingPolicy, GeneratingPolicy, DeletingPolicy, and ImageValidatingPolicy. Trigger when the user asks whether an admission policy is safe, whether a PolicyException is justified, whether a policy should be enforced or audited, whether a Kyverno policy should be replaced by a native ValidatingAdmissionPolicy (CEL), or whether image signature verification is correctly configured.
allowed-tools	Read Grep Glob
metadata	{"author":"github: Raishin","version":"0.1.0","updated":"2026-05-05","category":"security"}

Kyverno Policy Review

Purpose

Review Kyverno policies and PolicyExceptions against admission correctness, supply chain integrity, blast radius, failure mode, and the Kyverno-vs-native-CEL architectural decision. Kyverno is the most widely deployed Kubernetes policy engine — every misconfigured policy is either a silent allow (security gap) or a silent deny (production outage).

Lean operating rules

• Prefer live cluster evidence (kubectl get policies.kyverno.io,clusterpolicies,policies,validatingpolicies,mutatingpolicies,imagevalidatingpolicies,policyexceptions -A -o yaml) when the active client exposes it; otherwise fall back to official Kyverno documentation (kyverno.io) and sanitized YAML from the user.
• Separate confirmed facts from inference. If the cluster's Kyverno install state, admission webhook configuration, or PolicyReport status was not queried, say so.
• Treat failureAction: Audit (or legacy validationFailureAction: audit) on a production-relevant policy as a critical finding — admission violations become silent log lines.
• Treat any PolicyException as an audit-required artifact — every exception is a documented bypass with a name, reason, and reviewer.
• Challenge background: false paired with no match admission scope — the policy will never run.
• Challenge ImageValidatingPolicy with verifyImages: skip patterns, missing public keys, or mutateDigest: false — supply-chain attestations stop being enforced or stop being immutable.
• Challenge any policy that could compile to a native ValidatingAdmissionPolicy (CEL) — fewer moving parts, no Kyverno controller in the admission path.
• Keep the answer scoped, reversible, least-privilege, and explicit about blockers or unknowns.

References

Load these only when needed:

• Evidence path and tooling — use when choosing live cluster evidence, confirming Kyverno install state, or switching to documentation mode.
• Workflow and output contract — use when executing the full review, applying stress checks, evaluating Kyverno-vs-native-CEL, or formatting the final answer.
• Official sources — use when you need the detailed Kyverno documentation list, CEL expression references, or grounded insights from the Kyverno project.

Response minimum

Return, at minimum:

• the scoped target (policy kind, name, match scope) and evidence level,
• the failure mode (Audit vs Enforce) and whether it matches the production posture,
• the main risks or control gaps (PolicyException, wildcard match, missing image signatures, weak CEL expressions),
• whether the policy could be replaced by a native ValidatingAdmissionPolicy (CEL) and the tradeoff,
• the safest next actions and rollback plan,
• the assumptions or blockers that prevent stronger conclusions.