CVE-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` 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.

CVSS v3 8.3 HIGH

8.3^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.6 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/coder/coder/pull/26154	Issue Tracking Patch
https://github.com/coder/coder/releases/tag/v2.29.17	Release Notes
https://github.com/coder/coder/releases/tag/v2.32.7	Release Notes
https://github.com/coder/coder/releases/tag/v2.33.8	Release Notes
https://github.com/coder/coder/releases/tag/v2.34.2	Release Notes
https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:coder:coder::::::go::*
	cpe:2.3:a:coder:coder::::::go::*
	cpe:2.3:a:coder:coder::::::go::*
	cpe:2.3:a:coder:coder::::::go::*

History

No history.

Information

Published : 2026-07-08 00:16

Updated : 2026-07-08 19:44

NVD link : CVE-2026-55427

Mitre link : CVE-2026-55427

CVE.ORG link : CVE-2026-55427

JSON object : View

Products Affected

coder

coder

CWE

CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CWE-78

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

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