Netty: [codec-http2] Lack of Host Header Deduplication in HTTP/2→HTTP/1.x Translation Leads to Request Routing Bypass

中 5.3CVE-2026-59900 · GHSA-c69g-56f8-xwqj · 29/07/2026 公開 · 06/08/2026 更新

要点

CVE-2026-59900 は io.netty:netty-codec-http2, netty (netty) に影響する深刻度「中」 (CVSS 5.3) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.40%（全脆弱性の 34.1% より高い）。
対処：4.2.16.Final, 4.1.136.Final, 4.2.16, 4.1.136 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
io.netty:netty-codec-http2 Maven	`≥ 4.2.0.Final, < 4.2.16.Final< 4.1.136.Final`	`4.2.16.Final4.1.136.Final`
netty netty	`≥ 4.2.0, < 4.2.16< 4.1.136`	`4.2.164.1.136`

概要

Netty's HTTP/2-to-HTTP/1.x translation layer (Http2StreamFrameToHttpObjectCodec and InboundHttp2ToHttpAdapter) fails to deduplicate or validate Host headers when an HTTP/2 client supplies both the :authority pseudo-header and a literal host header in a single HEADERS frame. The translator maps :authority to Host and separately copies the literal host header, producing an HttpRequest object containing two Host headers with attacker-controlled differing values.

NVD の説明

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (`Http2StreamFrameToHttpObjectCodec` and `InboundHttp2ToHttpAdapter`) fails to deduplicate or validate `Host` headers when an HTTP/2 client supplies both the `:authority` pseudo-header and a literal `host` header in a single HEADERS frame. The translator maps `:authority` to `Host` and separately copies the literal `host` header, producing an `HttpRequest` object containing two `Host` headers with attacker-controlled differing values. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.