CVE-2026-55427
Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Timeline
ID reserved
By GitHub_M
- 21 days later
· 21 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.47% · top 59% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Weakness
- CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (opens in a new tab)All about CWE-74 and its CVEs
- CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (opens in a new tab)All about CWE-78 and its CVEs
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/coder/coder/v2GHSA-mcqq-fqgf-rxwm (opens in a new tab)
References (6)
- https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm (opens in a new tab)x_refsource_CONFIRM
- https://github.com/coder/coder/pull/26154 (opens in a new tab)x_refsource_MISC
- https://github.com/coder/coder/releases/tag/v2.29.17 (opens in a new tab)x_refsource_MISC
- https://github.com/coder/coder/releases/tag/v2.32.7 (opens in a new tab)x_refsource_MISC
- https://github.com/coder/coder/releases/tag/v2.33.8 (opens in a new tab)x_refsource_MISC
- https://github.com/coder/coder/releases/tag/v2.34.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-mcqq-fqgf-rxwm (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55427)Record last updated .