CVE-2025-71399

Description

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.

References

https://www.vulncheck.com/advisories/better-auth-before-path-normalization-bypass-via-rou3

https://github.com/better-auth/better-auth/security/advisories/GHSA-x732-6j76-qmhm

https://github.com/better-auth/better-auth/commit/f60b43fa648399534507c9ac7db36d705b8874c3

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4