{"id":"CVE-2026-73430","title":"Russh is a Rust SSH client & server library","summary":"Russh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSH_MSG_KEX_ECDH_INIT with a 32-byte all-zero Q_C value. Curve25519Kex::server_dh in russh/src/kex/curve…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-754"],"vendor":"russh","product":"russh","affected":["russh < 0.62.4"],"patched":["russh 0.62.4"],"published":"2026-08-12","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:02:22.660","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-73430","references":[{"url":"https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d","label":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.62.4","label":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r","label":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh"}],"tags":["nvd","osv","rust"],"epss":0.00332,"epssPercentile":0.2665,"aliases":["GHSA-5xvq-cp9x-6p6r"],"ecosystem":"rust","ingestedAt":"2026-08-13T19:18:22.025Z","slug":"CVE-2026-73430","body":"## Overview\n\nRussh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSH_MSG_KEX_ECDH_INIT with a 32-byte all-zero Q_C value. Curve25519Kex::server_dh in russh/src/kex/curve25519.rs accepts the all-zero peer public value and computes an all-zero shared secret, after which compute_exchange_hash calls encode_mpint in russh/src/kex/mod.rs and indexes beyond the end of the input while skipping leading zero bytes. The resulting panic occurs before authentication and terminates the server key-exchange task. This issue is fixed in version 0.62.4.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-73430)\n\nAffected packages:\n\n- `russh < 0.62.4`\n\nPatched in:\n\n- `russh 0.62.4`\n\nSource: https://osv.dev/vulnerability/GHSA-5xvq-cp9x-6p6r","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}