{"id":"CVE-2026-102823","state":"PUBLISHED","title":"russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened","description":"Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CHANNEL_REQUEST subtypes exit-status, exit-signal, and xon-xoff to public client::Handler callbacks without confirming that the ChannelId belongs to a channel the client opened and established. A malicious SSH server can send lifecycle events for predicted, unopened, unconfirmed, or released channel identifiers, causing application panics or corrupting command completion and exit-code tracking. This issue is fixed in version 0.63.1.","publishedAt":"2026-09-29T18:25:58.084Z","updatedAt":"2026-10-02T12:20:10.605Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["Eugeny russh"],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.63.1","status":"affected"}]}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm","https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774","https://github.com/Eugeny/russh/releases/tag/v0.63.1"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/102xxx/CVE-2026-102823.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-102823","state":"PUBLISHED","datePublished":"2026-09-29T18:25:58.084Z","dateUpdated":"2026-10-02T12:20:10.605Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-29T17:25:25.265Z"},"containers":{"cna":{"title":"russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened","descriptions":[{"lang":"en","value":"Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CHANNEL_REQUEST subtypes exit-status, exit-signal, and xon-xoff to public client::Handler callbacks without confirming that the ChannelId belongs to a channel the client opened and established. A malicious SSH server can send lifecycle events for predicted, unopened, unconfirmed, or released channel identifiers, causing application panics or corrupting command completion and exit-code tracking. This issue is fixed in version 0.63.1."}],"affected":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.63.1","status":"affected"}]}],"references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm","name":"https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774","name":"https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774","tags":["x_refsource_MISC"]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.63.1","name":"https://github.com/Eugeny/russh/releases/tag/v0.63.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-29T18:25:58.084Z"},"source":{"advisory":"GHSA-47hw-gvq5-r2gm","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-02T12:19:44.206468Z","id":"CVE-2026-102823","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-02T12:20:10.605Z"}}]}}}