Better Auth before 1.4.5 Path Normalization Bypass via rou3
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.
CVE-2025-71399
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-71399
better-auth
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "better-auth",
"product": "better-auth",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "1.4.5",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "1.4.5",
"versionType": "semver"
}
],
"packageURL": "pkg:npm/better-auth",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2025-71399
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #12642 · Revision 1
- Added to Heist Feed
- Publisher date