Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
Summary
| CVE | CVE-2026-55427 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-08 00:16:33 UTC |
| Updated | 2026-07-08 19:44:24 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 8.3 HIGH from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Problem Types: CWE-74 | CWE-78 | CWE-74 CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') | CWE-78 CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.3 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 8.3 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
RequiredScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/coder/coder/releases/tag/v2.34.2 | [email protected] | github.com | Release Notes |
| github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm | [email protected] | github.com | Patch, Vendor Advisory |
| github.com/coder/coder/releases/tag/v2.29.17 | [email protected] | github.com | Release Notes |
| github.com/coder/coder/releases/tag/v2.32.7 | [email protected] | github.com | Release Notes |
| github.com/coder/coder/pull/26154 | [email protected] | github.com | Issue Tracking, Patch |
| github.com/coder/coder/releases/tag/v2.33.8 | [email protected] | github.com | Release Notes |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.