๐Ÿ›ก๏ธ CVE-2026-45364
๐ŸŸ  CVSS 8.0 โ€” High โœ… No Known Exploit CWE-307 NVD
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical /64 allocation could rotate through 2^64 distinct source addresses without exhausting the per-address counter, defeating rate limiting on /sign-in/email, /sign-up/email, /forget-password, and every other path the limiter protects. The same bug allowed a single client to vary the textual encoding of one IPv6 address (uppercase, compression, IPv4-mapped, hex-encoded IPv4-in-IPv6) and produce multiple distinct keys. This vulnerability is fixed in 1.4.17 and 1.5.0-beta.9.

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CWE CWE-307
Public Exploit โœ… No
Source NVD
Published 2026-05-15
Updated 2026-06-10
Modified 2026-06-09
Fix URL N/A

Affected Packages

Software From version Fixed in
better-auth โ€” โ€”
unknown โ€” โ€”

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