{"id":"CVE-2026-73430","state":"PUBLISHED","title":"Russh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB)","description":"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/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.","publishedAt":"2026-08-12T20:55:38.202Z","updatedAt":"2026-08-13T17:53:22.532Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["Eugeny russh"],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.62.4","status":"affected"}]}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r","https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d","https://github.com/Eugeny/russh/releases/tag/v0.62.4"],"weaknesses":["CWE-754"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73430.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73430","state":"PUBLISHED","datePublished":"2026-08-12T20:55:38.202Z","dateUpdated":"2026-08-13T17:53:22.532Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-12T14:32:11.796Z"},"containers":{"cna":{"title":"Russh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB)","descriptions":[{"lang":"en","value":"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/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."}],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.62.4","status":"affected"}]}],"references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r","name":"https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d","name":"https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d","tags":["x_refsource_MISC"]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.62.4","name":"https://github.com/Eugeny/russh/releases/tag/v0.62.4","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-754","lang":"en","description":"CWE-754: Improper Check for Unusual or Exceptional Conditions","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-12T20:55:38.202Z"},"source":{"advisory":"GHSA-5xvq-cp9x-6p6r","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-13T17:49:19.811444Z","id":"CVE-2026-73430","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-13T17:53:22.532Z"}}]}}}