{"id":"CVE-2026-102824","state":"PUBLISHED","title":"Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange","description":"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.","publishedAt":"2026-09-29T18:27:41.650Z","updatedAt":"2026-09-30T20:24:58.381Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["Eugeny russh"],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.63.0","status":"affected"}]}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-w3jg-pjxf-73p4","https://github.com/Eugeny/russh/commit/8da8967f196472576b1565d518a0ed60fce60f0c","https://github.com/Eugeny/russh/releases/tag/v0.63.0"],"weaknesses":["CWE-327"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/102xxx/CVE-2026-102824.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-102824","state":"PUBLISHED","datePublished":"2026-09-29T18:27:41.650Z","dateUpdated":"2026-09-30T20:24:58.381Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-29T17:25:25.265Z"},"containers":{"cna":{"title":"Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.63.0","status":"affected"}]}],"references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-w3jg-pjxf-73p4","name":"https://github.com/Eugeny/russh/security/advisories/GHSA-w3jg-pjxf-73p4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Eugeny/russh/commit/8da8967f196472576b1565d518a0ed60fce60f0c","name":"https://github.com/Eugeny/russh/commit/8da8967f196472576b1565d518a0ed60fce60f0c","tags":["x_refsource_MISC"]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.63.0","name":"https://github.com/Eugeny/russh/releases/tag/v0.63.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-327","lang":"en","description":"CWE-327: Use of a Broken or Risky Cryptographic Algorithm","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-29T18:27:41.650Z"},"source":{"advisory":"GHSA-w3jg-pjxf-73p4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-30T20:24:54.936526Z","id":"CVE-2026-102824","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-30T20:24:58.381Z"}}]}}}