{"id":"CVE-2025-71399","sourceIdentifier":"disclosure@vulncheck.com","published":"2026-08-02T13:16:52.210","lastModified":"2026-10-08T16:16:53.243","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"Better Auth relies on better-call, which uses the rou3 router library. In affected versions of rou3, paths are normalized by removing empty segments, so /path, //path, and ///path resolve to the same route. In Better Auth versions prior to 1.4.5 (which bundles the fixed rou3), this can allow attackers to bypass disabledPaths configuration and path-based rate limits by submitting requests with extra slashes in the URL path. The issue does not apply in deployments where the proxy or platform normalizes URLs by collapsing multiple slashes."},{"lang":"es","value":"Better Auth depende de better-call, que utiliza la biblioteca de router rou3. En versiones afectadas de rou3, las rutas se normalizan eliminando segmentos vacíos, por lo que /path, //path y ///path se resuelven a la misma ruta. En versiones de Better Auth anteriores a la 1.4.5 (que incluye el rou3 corregido), esto puede permitir a los atacantes eludir la configuración de disabledPaths y los límites de tasa basados en rutas enviando solicitudes con barras adicionales en la ruta de la URL. El problema no se aplica en implementaciones donde el proxy o la plataforma normaliza las URL colapsando múltiples barras."}],"affected":[{"source":"disclosure@vulncheck.com","affectedData":[{"vendor":"better-auth","product":"better-auth","defaultStatus":"unaffected","packageURL":"pkg:npm/better-auth","versions":[{"version":"0","lessThan":"1.4.5","versionType":"semver","status":"affected"},{"version":"1.4.5","versionType":"semver","status":"unaffected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"disclosure@vulncheck.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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","baseScore":8.8,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"disclosure@vulncheck.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","baseScore":8.6,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":4.7}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-03T15:48:08.348859Z","id":"CVE-2025-71399","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"disclosure@vulncheck.com","type":"Secondary","description":[{"lang":"en","value":"CWE-20"}]}],"references":[{"url":"https://github.com/better-auth/better-auth/commit/f60b43fa648399534507c9ac7db36d705b8874c3","source":"disclosure@vulncheck.com"},{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-x732-6j76-qmhm","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/better-auth-before-path-normalization-bypass-via-rou3","source":"disclosure@vulncheck.com"}]}