CVE-2026-116794

HIGH

MEDIUM Priority: 0.01 BB Relevance: 42/100

Published: 2026-10-28 Modified: 2026-10-28 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Local

AC: Low

PR: Low

UI: None

AT: None

VC: None

VI: High

VA: None

Description

russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From 0.50.0-beta.12 until 0.65.0, the agent server's Connection::try_sign path in russh/src/keys/agent/server.rs recognizes SSH_AGENT_CONSTRAIN_CONFIRM but returns a hard-coded successful result instead of calling Agent::confirm. In applications that override Agent::confirm to require user approval or another policy check, a process that can reach the agent socket, including the remote side of a forwarded agent, can use a key added through ssh-add -c without that check and can authenticate or sign data as the user while the key remains loaded. The separate Agent::confirm_request hook still runs for every signing request, so checks implemented there remain effective, and implementations that retain the default always-successful Agent::confirm do not lose an approval check through this regression. This issue is fixed in version 0.65.0.