CVE-2026-55427
Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/coder/coder/v2 | >= 2.34.0, < 2.34.2 | 2.34.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Coder | Coder | before 2.29.17 from 2.30.0 before 2.32.7 from 2.33.0 before 2.33.8 from 2.34.0 before 2.34.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-mcqq-fqgf-rxwm
- 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