Vulnerability · Published Jul 7, 2026 · Assigned by GitHub_M

CVE-2026-55427Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`

High 8.3

In plain English

A high-severity injection in coder from coder. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.3High

Exploit odds (30 days)0.5%top 59.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/coder/coder	no fix listed	GO-2026-5913
Go	github.com/coder/coder/v2	2.34.2	GHSA-mcqq-fqgf-rxwm
Go	github.com/coder/coder/v2	2.33.8	GHSA-mcqq-fqgf-rxwm
Go	github.com/coder/coder/v2	2.32.7	GHSA-mcqq-fqgf-rxwm
Go	github.com/coder/coder/v2	2.29.17	GHSA-mcqq-fqgf-rxwm
Go	github.com/coder/coder/v2	2.29.17, 2.32.7, 2.33.8, 2.34.2	GO-2026-5913

Affected products (as reported)

Vendor	Product	Versions
coder	coder	>= 2.34.0, < 2.34.2>= 2.33.0, < 2.33.8>= 2.30.0, < 2.32.7< 2.29.17

Weakness: CWE-74, CWE-78 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

References

https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm x_refsource_CONFIRM
https://github.com/coder/coder/pull/26154 x_refsource_MISC
https://github.com/coder/coder/releases/tag/v2.29.17 x_refsource_MISC
https://github.com/coder/coder/releases/tag/v2.32.7 x_refsource_MISC
https://github.com/coder/coder/releases/tag/v2.33.8 x_refsource_MISC
https://github.com/coder/coder/releases/tag/v2.34.2 x_refsource_MISC