CVE-2026-45364

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{"affected": [{"affectedData": [{"product": "better-auth", "vendor": "better-auth", "versions": [{"status": "affected", "version": "< 1.4.17"}, {"status": "affected", "version": ">= 1.5.0-beta.1, < 1.5.0-beta.9"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical /64 allocation could rotate through 2^64 distinct source addresses without exhausting the per-address counter, defeating rate limiting on /sign-in/email, /sign-up/email, /forget-password, and every other path the limiter protects. The same bug allowed a single client to vary the textual encoding of one IPv6 address (uppercase, compression, IPv4-mapped, hex-encoded IPv4-in-IPv6) and produce multiple distinct keys. This vulnerability is fixed in 1.4.17 and 1.5.0-beta.9."}, {"lang": "es", "value": "Better Auth es una biblioteca de autenticaci\u00f3n y autorizaci\u00f3n para TypeScript. Antes de 1.4.17 y 1.5.0-beta.9, el limitador de tasa HTTP de Better Auth identificaba cada solicitud por la direcci\u00f3n IP textual exacta que recib\u00eda en x-forwarded-for (o el encabezado configurado que conten\u00eda la IP). Clientes IPv6 que controlaban una asignaci\u00f3n /64 t\u00edpica pod\u00edan rotar a trav\u00e9s de 2^64 direcciones de origen distintas sin agotar el contador por direcci\u00f3n, eludiendo la limitaci\u00f3n de tasa en /sign-in/email, /sign-up/email, /forget-password y cualquier otra ruta que el limitador protegiera. El mismo error permit\u00eda a un \u00fanico cliente variar la codificaci\u00f3n textual de una direcci\u00f3n IPv6 (may\u00fasculas, compresi\u00f3n, mapeada a IPv4, IPv4 codificada en hexadecimal en IPv6) y producir m\u00faltiples claves distintas. Esta vulnerabilidad est\u00e1 corregida en 1.4.17 y 1.5.0-beta.9."}], "id": "CVE-2026-45364", "lastModified": "2026-07-21T10:10:00.103", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 7.3, "baseSeverity": "HIGH", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.4, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-45364", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-29T19:05:14.121201Z", "version": "2.0.3"}}]}, "published": "2026-05-28T22:17:00.633", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/better-auth/better-auth/commit/43e719bcc0c223c7079fa0c611a9cf7ea1188254"}, {"source": "security-advisories@github.com", "url": "https://github.com/better-auth/better-auth/commit/57af0f7b910dcf7b1a5c0615d10b9bd56bb69bef"}, {"source": "security-advisories@github.com", "url": "https://github.com/better-auth/better-auth/pull/7470"}, {"source": "security-advisories@github.com", "url": "https://github.com/better-auth/better-auth/pull/7509"}, {"source": "security-advisories@github.com", "url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-p6v2-xcpg-h6xw"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-307"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

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