{"id":"UBUNTU-CVE-2026-102824","details":"Russh is a Rust SSH client and server library. Prior to 0.63.0, the hybrid ML-KEM 768 and X25519 implementation in russh/src/kex/hybrid_mlkem.rs accepts an all-zero 32-byte peer X25519 public key in both server_dh and compute_shared_secret, forcing the X25519 contribution to the combined shared secret to zero. A malicious SSH peer can therefore make the combined secret depend only on ML-KEM, defeating the hybrid exchange's intended fallback protection if ML-KEM is later weakened. This issue is fixed in version 0.63.0.","modified":"2026-10-17T12:57:56.698868315Z","published":"2026-09-29T19:17:00Z","upstream":["CVE-2026-102824"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-102824"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-102824"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/security/advisories/GHSA-w3jg-pjxf-73p4"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/commit/8da8967f196472576b1565d518a0ed60fce60f0c"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/releases/tag/v0.63.0"}],"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_version":"0.57.1-2","binary_name":"librust-russh-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-102824.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}