{"id":"CVE-2026-55427","state":"PUBLISHED","title":"Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`","description":"Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `coder config-ssh` wrote server-supplied SSH settings (`HostnameSuffix`, `SSHConfigOptions`) into the user's `~/.ssh/config` without sanitizing embedded newlines or restricting directives so a malicious or compromised Coder server could inject arbitrary SSH configuration. Practical exploitation requires control of the server-supplied values through a malicious or compromised deployment, a man-in-the-middle position or admin access to the `HostnameSuffix` and `SSHConfigOptions` settings. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates `HostnameSuffix` and `SSHConfigOptions` against a strict character set that rejects newlines and other control characters. As a workaround, inspect `coder config-ssh --dry-run` output before applying changes.","publishedAt":"2026-07-07T23:55:26.240Z","updatedAt":"2026-07-08T13:10:01.820Z","severity":{"score":8.3,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["coder coder"],"affected":[{"vendor":"coder","product":"coder","versions":[{"version":">= 2.34.0, < 2.34.2","status":"affected"},{"version":">= 2.33.0, < 2.33.8","status":"affected"},{"version":">= 2.30.0, < 2.32.7","status":"affected"},{"version":"< 2.29.17","status":"affected"}]}],"references":["https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm","https://github.com/coder/coder/pull/26154","https://github.com/coder/coder/releases/tag/v2.29.17","https://github.com/coder/coder/releases/tag/v2.32.7","https://github.com/coder/coder/releases/tag/v2.33.8","https://github.com/coder/coder/releases/tag/v2.34.2"],"weaknesses":["CWE-74","CWE-78"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55427.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55427","state":"PUBLISHED","datePublished":"2026-07-07T23:55:26.240Z","dateUpdated":"2026-07-08T13:10:01.820Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T21:48:43.126Z"},"containers":{"cna":{"title":"Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`","descriptions":[{"lang":"en","value":"Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `coder config-ssh` wrote server-supplied SSH settings (`HostnameSuffix`, `SSHConfigOptions`) into the user's `~/.ssh/config` without sanitizing embedded newlines or restricting directives so a malicious or compromised Coder server could inject arbitrary SSH configuration. Practical exploitation requires control of the server-supplied values through a malicious or compromised deployment, a man-in-the-middle position or admin access to the `HostnameSuffix` and `SSHConfigOptions` settings. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates `HostnameSuffix` and `SSHConfigOptions` against a strict character set that rejects newlines and other control characters. As a workaround, inspect `coder config-ssh --dry-run` output before applying changes."}],"affected":[{"vendor":"coder","product":"coder","versions":[{"version":">= 2.34.0, < 2.34.2","status":"affected"},{"version":">= 2.33.0, < 2.33.8","status":"affected"},{"version":">= 2.30.0, < 2.32.7","status":"affected"},{"version":"< 2.29.17","status":"affected"}]}],"references":[{"url":"https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm","name":"https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/coder/coder/pull/26154","name":"https://github.com/coder/coder/pull/26154","tags":["x_refsource_MISC"]},{"url":"https://github.com/coder/coder/releases/tag/v2.29.17","name":"https://github.com/coder/coder/releases/tag/v2.29.17","tags":["x_refsource_MISC"]},{"url":"https://github.com/coder/coder/releases/tag/v2.32.7","name":"https://github.com/coder/coder/releases/tag/v2.32.7","tags":["x_refsource_MISC"]},{"url":"https://github.com/coder/coder/releases/tag/v2.33.8","name":"https://github.com/coder/coder/releases/tag/v2.33.8","tags":["x_refsource_MISC"]},{"url":"https://github.com/coder/coder/releases/tag/v2.34.2","name":"https://github.com/coder/coder/releases/tag/v2.34.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.3,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-74","lang":"en","description":"CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-78","lang":"en","description":"CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-07T23:55:26.240Z"},"source":{"advisory":"GHSA-mcqq-fqgf-rxwm","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-08T13:09:33.858876Z","id":"CVE-2026-55427","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-08T13:10:01.820Z"}}]}}}