CVE-2026-75833

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Following a legitimate OAuth login flow, an attacker-supplied returnTo parameter could redirect an authenticated victim to an attacker-controlled site for post-login phishing. Full browser-side exploitability depends on the admin-next SPA's client-side oauth-callback handler and was not independently verified by the reporter."}, {"lang": "es", "value": "El plugin API de Grav (getgrav/grav-plugin-api, incluido con la pila admin-next/API de Grav 2.0) anterior a la versi\u00f3n 1.0.14 contiene una debilidad de redirecci\u00f3n abierta en SsoController::sanitizeReturnTo(). La funci\u00f3n rechaza un prefijo literal \u2019//\u2019 pero no tiene en cuenta que los navegadores normalizan las barras invertidas a barras en esquemas especiales (HTTP/HTTPS), por lo que un valor returnTo como \u2019/\\evil.com\u2019 pasa la protecci\u00f3n y es posteriormente resuelto por el navegador como la URL relativa al protocolo \u2019//evil.com\u2019. Tras un flujo de inicio de sesi\u00f3n OAuth leg\u00edtimo, un par\u00e1metro returnTo proporcionado por el atacante podr\u00eda redirigir a una v\u00edctima autenticada a un sitio controlado por el atacante para phishing posterior al inicio de sesi\u00f3n. La explotabilidad completa del lado del navegador depende del gestor oauth-callback del lado del cliente de la SPA admin-next y no fue verificada independientemente por el informante."}], "id": "CVE-2026-75833", "lastModified": "2026-10-22T22:10:00.250", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.2, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 2.5, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.6, "baseSeverity": "HIGH", "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/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": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-75833", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-18T13:41:12.267567Z", "version": "2.0.3"}}]}, "published": "2026-08-18T12:19:33.370", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/getgrav/grav/security/advisories/GHSA-x72c-4jc4-8rh6"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/grav-api-plugin-open-redirect-via-backslash-bypass"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-601"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

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