{"api_version":"1","generated_at":"2026-10-28T04:50:06+00:00","cve":"CVE-2026-116774","urls":{"html":"https://cve.report/CVE-2026-116774","api":"https://cve.report/api/cve/CVE-2026-116774.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-116774","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116774"},"summary":{"title":"russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)","description":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From 0.60.0 until 0.65.0, channel-open parsing accepts a peer-declared maximum_packet_size of zero and passes it into ChannelTx::poll_writable in russh/src/channels/io/tx.rs. The Channel::data, Channel::make_writer, and Channel::into_stream asynchronous write paths then calculate a writable size of zero and remain pending forever because window adjustments cannot satisfy a static zero packet maximum. An authenticated client can strand server writes, and a malicious server can strand client writes, allowing affected tasks, channels, and connections to accumulate without surfacing an error. This issue is fixed in version 0.65.0.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-10-27 21:18:05","updated_at":"2026-10-27 21:18:06"},"problem_types":["CWE-400","CWE-835","CWE-400 CWE-400: Uncontrolled Resource Consumption","CWE-835 CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"4.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","baseScore":4.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"4.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","name":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","name":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","name":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-116774","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116774","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Eugeny","product":"russh","version":"affected >= 0.60.0, < 0.65.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"russh","vendor":"Eugeny","versions":[{"status":"affected","version":">= 0.60.0, < 0.65.0"}]}],"descriptions":[{"lang":"en","value":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From 0.60.0 until 0.65.0, channel-open parsing accepts a peer-declared maximum_packet_size of zero and passes it into ChannelTx::poll_writable in russh/src/channels/io/tx.rs. The Channel::data, Channel::make_writer, and Channel::into_stream asynchronous write paths then calculate a writable size of zero and remain pending forever because window adjustments cannot satisfy a static zero packet maximum. An authenticated client can strand server writes, and a malicious server can strand client writes, allowing affected tasks, channels, and connections to accumulate without surfacing an error. This issue is fixed in version 0.65.0."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","description":"CWE-400: Uncontrolled Resource Consumption","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-835","description":"CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-27T20:25:26.914Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","tags":["x_refsource_CONFIRM"],"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42"},{"name":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","tags":["x_refsource_MISC"],"url":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c"},{"name":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","tags":["x_refsource_MISC"],"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0"}],"source":{"advisory":"GHSA-fw5c-8223-6h42","discovery":"UNKNOWN"},"title":"russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-116774","datePublished":"2026-10-27T20:25:26.914Z","dateReserved":"2026-10-26T21:53:35.166Z","dateUpdated":"2026-10-27T20:25:26.914Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-27 21:18:05","lastModifiedDate":"2026-10-27 21:18:06","problem_types":["CWE-400","CWE-835","CWE-400 CWE-400: Uncontrolled Resource Consumption","CWE-835 CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","baseScore":4.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":2.8,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"116774","Ordinal":"1","Title":"russh: peer-declared zero maximum packet size permanently stalls","CVE":"CVE-2026-116774","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"116774","Ordinal":"1","NoteData":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From 0.60.0 until 0.65.0, channel-open parsing accepts a peer-declared maximum_packet_size of zero and passes it into ChannelTx::poll_writable in russh/src/channels/io/tx.rs. The Channel::data, Channel::make_writer, and Channel::into_stream asynchronous write paths then calculate a writable size of zero and remain pending forever because window adjustments cannot satisfy a static zero packet maximum. An authenticated client can strand server writes, and a malicious server can strand client writes, allowing affected tasks, channels, and connections to accumulate without surfacing an error. This issue is fixed in version 0.65.0.","Type":"Description","Title":"russh: peer-declared zero maximum packet size permanently stalls"}]}}}