CVE-2026-3419

描述

# Description Fastify incorrectly accepts malformed `Content-Type` headers containing trailing characters after the subtype token, in violation of [RFC 9110 §8.3.1](https://httpwg.org/specs/rfc9110.html#field.content-type). For example, a request sent with `Content-Type: application/json garbage` passes validation and is processed normally, rather than being rejected with `415 Unsupported Media Type`. When regex-based content-type parsers are in use (a documented Fastify feature), the malformed value is matched against registered parsers using the full string including the trailing garbage. This means a request with an invalid content-type may be routed to and processed by a parser it should never have reached. ## Impact An attacker can send requests with RFC-invalid `Content-Type` headers that bypass validity checks, reach content-type parser matching, and be processed by the server. Requests that should be rejected at the validation stage are instead handled as if the content-type were valid. ## Workarounds Deploy a WAF rule to protect against this ## Fix The fix is available starting with v5.8.1.

如何修補 CVE-2026-3419

要修補 CVE-2026-3419,請將受影響套件升級到下列已修補版本。

• —升級至 5.8.1 或更新版本

CVE-2026-3419 正在被利用嗎?

低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• >= 5.7.2, < 5.8.1

CVSS 分數