CVE-2026-50243

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If the validator finds an expired or otherwise invalid RRSIG on an answer whose A record falls within a 'response-ip'/RPZ configuration, the answer is still rewritten and given a hard coded security level of INSECURE. This results in the client receiving an INSECURE NOERROR reply rewritten by the operator's configured IP. A malicious actor can exploit the possible poisonous effect by spoofing a BOGUS A/AAAA answer that falls inside the operator's configured subnet rewrites. Such DNSSEC protected answers are then insecurely redirected to the operator's configured target."}, {"lang": "es", "value": "En NLnet Labs Unbound 1.6.2 hasta la versi\u00f3n 1.25.1 inclusive, cuando Unbound est\u00e1 configurado con el m\u00f3dulo \u2019respip\u2019 delante del validador junto con una regla de redirecci\u00f3n \u2019response-ip\u2019 o un archivo RPZ con un disparador RPZ-IP, el gestor de reescritura no verifica el estado de seguridad de la respuesta ascendente y en su lugar puede reescribir una respuesta A/AAAA BOGUS para que apunte a una IP configurada por el operador. Si el validador encuentra un RRSIG caducado o de otro modo inv\u00e1lido en una respuesta cuyo registro A cae dentro de una configuraci\u00f3n \u2019response-ip\u2019/RPZ, la respuesta sigue siendo reescrita y se le asigna un nivel de seguridad codificado de INSEGURO. Esto resulta en que el cliente reciba una respuesta INSEGURA NOERROR reescrita por la IP configurada del operador. Un actor malicioso puede explotar el posible efecto venenoso suplantando una respuesta A/AAAA BOGUS que cae dentro de las reescrituras de subred configuradas por el operador. Dichas respuestas protegidas por DNSSEC son entonces redirigidas de forma insegura al objetivo configurado por el operador."}], "id": "CVE-2026-50243", "lastModified": "2026-10-24T13:10:00.147", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "sep@nlnetlabs.nl", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-50243", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-07-22T18:57:49.710450Z", "version": "2.0.3"}}]}, "published": "2026-07-22T14:17:20.240", "references": [{"source": "sep@nlnetlabs.nl", "tags": ["Vendor Advisory"], "url": "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50243.txt"}], "sourceIdentifier": "sep@nlnetlabs.nl", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-348"}], "source": "sep@nlnetlabs.nl", "type": "Secondary"}]}

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