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CVE-2025-71399

CVE-2025-71399 · Better Auth before 1.4.5 Path Normalization Bypass via rou3

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 8.8 · High · EPSS 0.5% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • better-auth

    Versions
    • ≥ 0, < 1.4.5: Affected (semver)
    • 1.4.5: Not affected (semver)

    Update to 1.4.5

  • better-auth npm

    Affected ranges
    • SEMVER: < 1.4.5

    Update to 1.4.5

Original sources

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