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CVE-2025-71399GHSA-X732-6J76-QMHM

Better Auth before 1.4.5 Path Normalization Bypass via rou3

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 1.4.5
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • better-auth better-auth

    fixed in 1.4.5

  • better-authnpm

    fixed in 1.4.5

References 3

GitHub · better-auth/better-auth

vulncheck.com