Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh

高 7.5CVE-2026-56855 · GO-2026-6355 · 02/09/2026 公開 · 04/09/2026 更新

要点

CVE-2026-56855 は golang.org/x/crypto, crypto (golang) に影響する深刻度「高」 (CVSS 7.5) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.50%（全脆弱性の 42.9% より高い）。
対処：0.56.0 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
golang.org/x/crypto Go	`< 0.56.0`	`0.56.0`
crypto golang	`< 0.56.0`	`0.56.0`

概要

Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection.

Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.

NVD の説明

Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.