[HIGH] CVE-2025-71399 — CVSS 8.6 (August 2, 2026)

A HIGH-severity vulnerability identified as CVE-2025-71399 has been published on August 2, 2026 with a CVSS base score of 8.6. This security advisory provides a detailed breakdown of the vulnerability, its potential impact, weakness classification, and actionable steps to protect your systems.

Vulnerability Details

CVE ID: CVE-2025-71399
Severity: HIGH
CVSS Score: 8.6
Published: August 2, 2026
Weakness (CWE): CWE-20

Technical 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.

Potential Impact

If exploited, this high-severity vulnerability could allow an attacker to cause a denial of service. Organizations running affected software should treat this as a priority remediation item.

Recommended Action

No official patch is available yet. Until one is released:

1. Monitor the official NVD page and vendor channels for patch announcements.
2. Restrict access to the affected system or service where possible.
3. Apply network-level mitigations such as firewall rules or WAF policies.
4. Enable logging and alerting for anomalous activity related to this vulnerability.
5. Review your incident response plan in case of active exploitation.

View full details on NVD →

References

• Reference 1
• Reference 2
• Reference 3

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