GHSA-573f-x89g-hqp9 · 深刻度： medium · エコシステム： npm — Fastify's Missing End Anchor in "subtypeNameReg" Allows Malformed Content-Types to Pass Validation
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.
総合評価: CVE-2026-3419 は低リスク（30.9/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.35%、27 パーセンタイル） 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.03% | 0.35% | +0.32% |
| 2 | 2026-03-07 | — | 0.03% | — |
EPSS の全履歴 （全 2 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | ce714d77-add3-4f53-aff5-83d477b104bb |
GHSA-573f-x89g-hqp9 · 深刻度： medium · エコシステム： npm — Fastify's Missing End Anchor in "subtypeNameReg" Allows Malformed Content-Types to Pass Validation
| vendor | priority | summary | link |
|---|---|---|---|
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-3419 |
| URL | タグ |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Vendor Advisory |
| https://github.com/advisories/GHSA-573f-x89g-hqp9 | Patch Vendor Advisory |
| https://github.com/fastify/fastify/commit/67f6c9b32cb3623d3c9470cc17ed830dd2f083d7 | Patch |
| https://github.com/fastify/fastify/security/advisories/GHSA-573f-x89g-hqp9 | Vendor Advisory |
| https://httpwg.org/specs/rfc9110.html#field.content-type | Technical Description |
| https://www.cve.org/CVERecord?id=CVE-2026-3419 | VDB Entry |