{"id":"UBUNTU-CVE-2026-116794","details":"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.","modified":"2026-11-04T03:30:34.517010150Z","published":"2026-11-03T00:00:00Z","upstream":["CVE-2026-116794"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-116794"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-116794"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/security/advisories/GHSA-vp5q-ff62-jwqv"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/commit/3e04597dc54e36bfc85c21996f7d8d9d224e9826"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/commit/62db6e7defd6d244159da962ccccb029e785ce0f"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0"}],"affected":[{"package":{"name":"rust-russh","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/rust-russh?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.57.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-russh-dev","binary_version":"0.57.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116794.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N"},{"type":"Ubuntu","score":"medium"}]}