{"id":"CVE-2026-116773","state":"PUBLISHED","title":"russh's SSH client is susceptible to unbounded allocations via EXT_INFO packets","description":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0.","publishedAt":"2026-10-27T20:23:25.559Z","updatedAt":"2026-10-30T15:17:49.289Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["Eugeny russh"],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.65.0","status":"affected"}]}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg","https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75","https://github.com/Eugeny/russh/releases/tag/v0.65.0"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-30T15:28:07.787Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/116xxx/CVE-2026-116773.json","commit":"2dd2c702f7243e3dc10f8d67fb014c71366252bc","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-116773","state":"PUBLISHED","datePublished":"2026-10-27T20:23:25.559Z","dateUpdated":"2026-10-30T15:17:49.289Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-26T21:53:35.165Z"},"containers":{"cna":{"title":"russh's SSH client is susceptible to unbounded allocations via EXT_INFO packets","descriptions":[{"lang":"en","value":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0."}],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.65.0","status":"affected"}]}],"references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg","name":"https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75","name":"https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75","tags":["x_refsource_MISC"]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","name":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-27T20:23:47.305Z"},"source":{"advisory":"GHSA-4p9f-7p9m-5vfg","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T15:17:39.066575Z","id":"CVE-2026-116773","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T15:17:49.289Z"}}]}}}