Patch Commitpatch
https://github.com/better-auth/better-auth/commit/f60b43fa648399534507c9ac7db36d705b8874c3 CVE-2025-71399
HIGH
Better Auth before 1.4.5 Path Normalization Bypass via rou3
Record summary
CVE-2025-71399 has a selected CVSS score of 8.8 (high).
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.
Description source: CVE List
Exploitation context
CISA SSVC decision
ExploitationNone
AutomatableYes
Technical impactPartial
CISA Coordinator · SSVC 2.0.3 · Evaluated Aug 3, 2026 · Source: CVE List
Affected products and versions
1| Product | Source | Version range | Status |
|---|---|---|---|
better-authBrowse better-auth / better-authDefault status: unaffected | CVE List | Before 1.4.5 | affected |
| 1.4.5 | unaffected |
References
4GitHub Security Advisory (GHSA-x732-6j76-qmhm)Vendor advisory
https://github.com/better-auth/better-auth/security/advisories/GHSA-x732-6j76-qmhm nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2025-71399 VulnCheck Advisory: Better Auth before 1.4.4 Path Normalization Bypass via rou3Third-party advisory
https://www.vulncheck.com/advisories/better-auth-before-path-normalization-bypass-via-rou3