CVE-2026-55427
published 2026-07-08CVE-2026-55427: 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`…
PriorityP349high8.3CVSS 3.1
AVNACHPRNUIRSCCHIHAH
EPSS
0.47%
39.6th percentile
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
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| coder | coder | < 2.29.17 | 2.29.17 |
| coder | coder | — | — |
| coder | coder | — | — |
| coder | coder | — | — |
| coder | coder | >= 2.30.0 < 2.32.7 | 2.32.7 |
| coder | coder | >= 2.33.0 < 2.33.8 | 2.33.8 |
| coder | coder | >= 2.34.0 < 2.34.2 | 2.34.2 |
| github.com | coder_coder_v2 | >= 0 < 2.29.17 | 2.29.17 |
| github.com | coder_coder_v2 | >= 2.30.0 < 2.32.7 | 2.32.7 |
| github.com | coder_coder_v2 | >= 2.33.0 < 2.33.8 | 2.33.8 |
| github.com | coder_coder_v2 | >= 2.34.0 < 2.34.2 | 2.34.2 |
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VulDB
Coder up to 2.29.16/2.32.6/2.33.7/2.34.1 SSH Config HostnameSuffix/SSHConfigOptions injection
vuldb·2026-07-08·CVSS 8.3
CVE-2026-55427 [HIGH] Coder up to 2.29.16/2.32.6/2.33.7/2.34.1 SSH Config HostnameSuffix/SSHConfigOptions injection
A vulnerability described as critical has been identified in Coder up to 2.29.16/2.32.6/2.33.7/2.34.1. Affected is an unknown function of the component SSH Config Handler. Executing a manipulation of the argument HostnameSuffix/SSHConfigOptions can lead to injection.
This vulnerability appears as CVE-2026-55427. The attack may be performed from remote. There is no available exploit.
GHSA
Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
ghsa·2026-07-06
CVE-2026-55427 [HIGH] CWE-74 Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
### Summary
`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.
> **Note:** 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.
### Impact
A server administrator or an attacker who controlled the server, could inject a directive such as `ProxyCommand` and achieve arbitrary code execution on any developer
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://github.com/coder/coder/pull/26154https://github.com/coder/coder/releases/tag/v2.29.17https://github.com/coder/coder/releases/tag/v2.32.7https://github.com/coder/coder/releases/tag/v2.33.8https://github.com/coder/coder/releases/tag/v2.34.2https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm
2026-07-08
Published