CVE-2026-48713

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{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-48713", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-16T12:49:11.525388Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-16T12:49:21.463Z"}}], "cna": {"title": "i18next-fs-backend: Prototype pollution via crafted missing-key string", "source": {"advisory": "GHSA-2933-q333-qg83", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "i18next", "product": "i18next-fs-backend", "versions": [{"status": "affected", "version": "< 2.6.6"}]}], "references": [{"url": "https://github.com/i18next/i18next-fs-backend/security/advisories/GHSA-2933-q333-qg83", "name": "https://github.com/i18next/i18next-fs-backend/security/advisories/GHSA-2933-q333-qg83", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/i18next/i18next-fs-backend/commit/3ab0448087da6935a40117f904b7457281f963f4", "name": "https://github.com/i18next/i18next-fs-backend/commit/3ab0448087da6935a40117f904b7457281f963f4", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "Versions prior to 2.6.6 are vulnerable to prototype pollution via crafted missing-key strings when used to persist missing translation keys (e.g. via i18next-http-middleware's missingKeyHandler exposed to untrusted input). Backend.writeFile() splits each queued missing-key string on the configured keySeparator (default .) before calling the internal setPath() walker. The walker (getLastOfPath in lib/utils.js) did not guard against unsafe segments, so a key like \"__proto__.polluted\" was split into [\"__proto__\", \"polluted\"] and walked straight into Object.prototype, allowing an attacker to write arbitrary properties onto the global object prototype. Depending on the host application, polluted prototype properties may cause crashes, corrupted translation behaviour, configuration poisoning, or bypasses of property-based security checks. Applications are affected only if the missingKeyHandler (or another route that forwards untrusted request bodies to i18next.t(..., { ... }) with saveMissing: true) is reachable by untrusted users and the default behaviour of splitting missing-key strings on keySeparator is in use (i.e. keySeparator is not false). Apps that do not expose missing-key persistence to untrusted input are not directly affected through this attack path. This issue has been fixed in version 2.6.6. If developers using the library are unable to upgrade immediately, they should take the following precautions: do not expose i18next-http-middleware's missingKeyHandler to untrusted users (mount it behind authentication, or remove the route), disable missing-key persistence (saveMissing: false, or no backend.create implementation) when accepting writes from untrusted input, and set keySeparator: false in their i18next options to disable backend key splitting (note: this also disables nested translation keys)."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-1321", "description": "CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-06-15T20:31:53.929Z"}}}, "cveMetadata": {"cveId": "CVE-2026-48713", "state": "PUBLISHED", "dateUpdated": "2026-06-16T12:49:24.673Z", "dateReserved": "2026-05-22T18:47:27.755Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-06-15T20:31:53.929Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "i18next-fs-backend", "vendor": "i18next", "versions": [{"status": "affected", "version": "< 2.6.6"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:i18next:i18next-fs-backend:*:*:*:*:*:node.js:*:*", "matchCriteriaId": "231766DC-5AE8-42B2-886B-3536F229B128", "versionEndExcluding": "2.6.6", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Versions prior to 2.6.6 are vulnerable to prototype pollution via crafted missing-key strings when used to persist missing translation keys (e.g. via i18next-http-middleware's missingKeyHandler exposed to untrusted input). Backend.writeFile() splits each queued missing-key string on the configured keySeparator (default .) before calling the internal setPath() walker. The walker (getLastOfPath in lib/utils.js) did not guard against unsafe segments, so a key like \"__proto__.polluted\" was split into [\"__proto__\", \"polluted\"] and walked straight into Object.prototype, allowing an attacker to write arbitrary properties onto the global object prototype. Depending on the host application, polluted prototype properties may cause crashes, corrupted translation behaviour, configuration poisoning, or bypasses of property-based security checks. Applications are affected only if the missingKeyHandler (or another route that forwards untrusted request bodies to i18next.t(..., { ... }) with saveMissing: true) is reachable by untrusted users and the default behaviour of splitting missing-key strings on keySeparator is in use (i.e. keySeparator is not false). Apps that do not expose missing-key persistence to untrusted input are not directly affected through this attack path. This issue has been fixed in version 2.6.6. If developers using the library are unable to upgrade immediately, they should take the following precautions: do not expose i18next-http-middleware's missingKeyHandler to untrusted users (mount it behind authentication, or remove the route), disable missing-key persistence (saveMissing: false, or no backend.create implementation) when accepting writes from untrusted input, and set keySeparator: false in their i18next options to disable backend key splitting (note: this also disables nested translation keys)."}, {"lang": "es", "value": "Versiones anteriores a la 2.6.6 son vulnerables a la contaminaci\u00f3n de prototipos a trav\u00e9s de cadenas de claves faltantes manipuladas cuando se utilizan para persistir claves de traducci\u00f3n faltantes (por ejemplo, a trav\u00e9s del missingKeyHandler de i18next-HTTP-middleware expuesto a entrada no confiable). Backend.writeFile() divide cada cadena de clave faltante en cola en el keySeparator configurado (por defecto .) antes de llamar al \u201cwalker\u201d interno setPath(). El \u201cwalker\u201d (getLastOfPath en lib/utils.js) no proteg\u00eda contra segmentos inseguros, por lo que una clave como \u2019__proto__.polluted\u2019 se divid\u00eda en [\u2019__proto__\u2019, \u2019polluted\u2019] y se dirig\u00eda directamente a Object.prototype, permitiendo a un atacante escribir propiedades arbitrarias en el prototipo del objeto global. Dependiendo de la aplicaci\u00f3n anfitriona, las propiedades de prototipo contaminadas pueden causar fallos, comportamiento de traducci\u00f3n corrupto, envenenamiento de la configuraci\u00f3n o eludir las comprobaciones de seguridad basadas en propiedades. Las aplicaciones se ven afectadas solo si el missingKeyHandler (u otra ruta que reenv\u00ede cuerpos de solicitud no confiables a i18next.t(..., { ... }) con saveMissing: true) es accesible por usuarios no confiables y el comportamiento predeterminado de dividir las cadenas de claves faltantes en keySeparator est\u00e1 en uso (es decir, keySeparator no es false). Las aplicaciones que no exponen la persistencia de claves faltantes a entrada no confiable no se ven directamente afectadas a trav\u00e9s de esta ruta de ataque. Este problema ha sido solucionado en la versi\u00f3n 2.6.6. Si los desarrolladores que utilizan la biblioteca no pueden actualizar de inmediato, deben tomar las siguientes precauciones: no exponer el missingKeyHandler de i18next-HTTP-middleware a usuarios no confiables (montarlo detr\u00e1s de autenticaci\u00f3n, o eliminar la ruta), deshabilitar la persistencia de claves faltantes (saveMissing: false, o ninguna implementaci\u00f3n de backend.create) al aceptar escrituras de entrada no confiable, y establecer keySeparator: false en sus opciones de i18next para deshabilitar la divisi\u00f3n de claves del backend (nota: esto tambi\u00e9n deshabilita las claves de traducci\u00f3n anidadas)."}], "id": "CVE-2026-48713", "lastModified": "2026-10-25T23:10:00.167", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-48713", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-06-16T12:49:11.525388Z", "version": "2.0.3"}}]}, "published": "2026-06-15T22:16:17.397", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/i18next/i18next-fs-backend/commit/3ab0448087da6935a40117f904b7457281f963f4"}, {"source": "security-advisories@github.com", "tags": ["Mitigation", "Vendor Advisory"], "url": "https://github.com/i18next/i18next-fs-backend/security/advisories/GHSA-2933-q333-qg83"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1321"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.6.6)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "i18next-fs-backend", "source": "cna", "vendor": "i18next"}, "product": "i18next-fs-backend", "vendor": "i18next"}], "created": "2026-06-16T03:15:14.498631+00:00", "updated": "2026-06-17T23:00:14.713356+00:00", "vendors": ["i18next", "i18next$PRODUCT$i18next-fs-backend"]}