CVE-2026-122321

Kyverno from 1.11.0 before 1.19.2 contains an unbounded decompression vulnerability in FetchSignatureBlob that allows attackers to exhaust memory by supplying highly compressed notary signature layers. Attackers who control registry referrers or signatures can publish small gzip layers that decompress beyond maxPayloadSize, causing admission controller OOM kills and denial of service.

Kyverno from 1.11.0 before 1.19.2 contains an unbounded decompression vulnerability in extractStatement. Attackers controlling registry referrer artifacts can supply highly compressed attestation layers that exceed maxPayloadSize when decompressed, causing admission controller OOM kills and denial of service.

Kyverno before 1.19.2 contains a missing authorization vulnerability that allows namespaced Policy authors to read resources in other namespaces by templating generate.clone or cloneList namespace values. Attackers can annotate a triggering ConfigMap so the background-controller copies a victim namespace's sensitive ConfigMap into the attacker's namespace, enabling cross-tenant data disclosure.

Kyverno before 1.19.2 contains a denial-of-service vulnerability in the In and NotIn operators that allows attackers to crash the policy engine via an unchecked type assertion. Attackers can submit resources whose JMESPath-evaluated values yield arrays of integers, booleans, or mixed types, triggering a panic that disrupts admission control and policy enforcement.

Kyverno before 1.19.2 contains an authentication bypass in matchCertificateData that skips verifyImages subject and subjectRegExp checks when the signing certificate has no Subject Alternative Name. Attackers holding a leaf certificate from a configured private trust root can omit the SAN, set the expected Fulcio issuer OID, and sign malicious images that are admitted despite signer pinning.

Kyverno from 1.17.0 before 1.19.2 contains a missing authorization vulnerability in the mutate-existing background processor that allows namespaced tenants to modify resources outside their namespace. Attackers can create a NamespacedMutatingPolicy targeting Namespace objects or victim-namespace resources via CEL expressions, making the background-controller ServiceAccount strip Pod Security labels cluster-wide.

Kyverno before 1.19.2 contains an unchecked type assertion in buildStatementMap that allows unauthenticated attackers to crash the policy engine via crafted attestation statements. Attackers can push an OCI referrer manifest with a non-string type field to bypass image verification under failurePolicy Ignore or crash-loop the reports-controller.

Kyverno before 1.19.2 contains an unchecked type assertion in its variable-substitution engine that allows users who can submit resources to crash the policy engine. Attackers can submit resources with non-string fields referenced by {{- variable }} shallow substitution in policies, causing a panic that yields webhook denial of service and policy bypass under failurePolicy Ignore.

Kyverno from 1.19.1 before 1.19.2 contains a namespace isolation bypass in APICall Fetch() in pkg/engine/apicall/apiCall.go because path.Clean treats '?' as a path character, letting the namespace regex match segments inside the query string. Users who can create namespaced policies can supply a URLPath like /api/v1/nodes?x=/namespaces/default/ that passes validation while client-go requests the cluster-scoped endpoint, reading resources outside their namespace.

Kyverno before 1.19.2 contains a denial of service vulnerability that allows namespace-scoped policy authors to exhaust CPU and memory by submitting CEL expressions evaluated without runtime cost limits. Attackers can create a NamespacedValidatingPolicy or NamespacedDeletingPolicy with nested map comprehensions over large ConfigMap fields to OOM-kill Kyverno pods and block cluster-wide admission.