CVE-2026-15144— @fastify/rate-limit vulnerable to rate-limit bypass via IPv6 address rotation

@fastify/rate-limit vulnerable to rate-limit bypass via IPv6 address rotation

@fastify/rate-limit before 11.2.0 keys rate-limit buckets by the verbatim client IP string returned from request.ip. Because a single IPv6 client can control a large address range (a /64 holds 2^64 distinct addresses) and the same address has multiple valid textual representations, an IPv6 capable client can defeat the rate-limit boundary by rotating addresses or by rewriting the same address in different forms. Applications that use @fastify/rate-limit to protect endpoints such as authentication, password reset, OTP delivery, or expensive API calls can be bypassed by IPv6 clients behind a proxy that surfaces IPv6 to the origin when trustProxy is enabled. The issue is fixed in @fastify/rate-limit 11.2.0, where the default key generator normalizes IPv6 addresses to their canonical form, collapses IPv4 mapped IPv6 to IPv4, and applies a configurable prefix mask (default /64) via a new ipv6Subnet option.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

过多认证尝试的限制不恰当

Fastify @fastify/rate-limit 授权问题漏洞

Fastify @fastify/rate-limit是Fastify组织的一个速率限制中间件。 Fastify @fastify/rate-limit 11.2.0之前版本存在安全漏洞，该漏洞源于使用原始客户端IP字符串作为速率限制键，导致IPv6客户端可以通过旋转地址或重写地址的不同形式绕过速率限制边界。

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