russh: Unbounded memory allocation in agent protocol server via crafted constraint records

影響: rust:russh <= 0.64.0 → 0.64.1

russh_keys::agent::server::add_key (russh/src/keys/agent/server.rs:271-319) spawns a dedicated tokio task for every 5-byte SSH_AGENT_CONSTRAIN_LIFETIME record attached to an added key, each cloning the key blob and sleeping for the declared lifetime (up to ~136 years). The loop has no per-request task budget, and spawned tasks are not rolled back when the overall request fails. Repeating one constrained add-key message over an agent connection converts wire bytes into resident tasks and…

在 GitHub Advisory Database 阅读

2026/10/20 02:06，GitHub Advisory Database 发布了“russh: Unbounded memory allocation in agent protocol server via crafted constraint records”（类型：漏洞公告）。严重程度为“中危”（medium）。相关技术：Rust。CVE：CVE-2026-111061。