Vulnerability-Lookup

GHSA-MCQQ-FQGF-RXWM

Vulnerability from github – Published: 2026-07-06 20:53 – Updated: 2026-07-06 20:53

Summary

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

Details

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 workstation that ran coder config-ssh. Injected commands ran with the local user's privileges and applied to all SSH connections, not just Coder workspaces.

Patches

The fix validates HostnameSuffix and SSHConfigOptions against a strict character set that rejects newlines and other control characters.

The fix was backported to all supported release lines:

Release line	Patched version
2.34	v2.34.2
2.33	v2.33.8
2.32	v2.32.7
2.29 (ESR)	v2.29.17

Workarounds

Inspect coder config-ssh --dry-run output before applying changes.

Resources

Fix: #26154

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22437) for independently disclosing this issue!

Severity

8.3 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.34.0"
            },
            {
              "fixed": "2.34.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.33.0"
            },
            {
              "fixed": "2.33.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.30.0"
            },
            {
              "fixed": "2.32.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.29.17"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55427"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-74",
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-06T20:53:54Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`coder config-ssh` wrote server-supplied SSH settings (`HostnameSuffix`, `SSHConfigOptions`) into the user\u0027s `~/.ssh/config` without sanitizing embedded newlines or restricting directives so a malicious or compromised Coder server could inject arbitrary SSH configuration.\n\n\u003e **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.\n\n### Impact\n\nA server administrator or an attacker who controlled the server, could inject a directive such as `ProxyCommand` and achieve arbitrary code execution on any developer workstation that ran `coder config-ssh`. Injected commands ran with the local user\u0027s privileges and applied to all SSH connections, not just Coder workspaces.\n\n### Patches\n\nThe fix validates `HostnameSuffix` and `SSHConfigOptions` against a strict character set that rejects newlines and other control characters.\n\nThe fix was backported to all supported release lines:\n\n| Release line | Patched version |\n|---|---|\n| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |\n| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |\n| 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) |\n| 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) |\n\n### Workarounds\n\nInspect `coder config-ssh --dry-run` output before applying changes.\n\n### Resources\n\n- Fix: #26154\n\n### Credits\n\nCoder would like to thank Anthropic\u0027s Security Team (ANT-2026-22437) for independently disclosing this issue!",
  "id": "GHSA-mcqq-fqgf-rxwm",
  "modified": "2026-07-06T20:53:54Z",
  "published": "2026-07-06T20:53:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/pull/26154"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/coder/coder"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`"
}

CVE-2026-55427 (GCVE-0-2026-55427)

Vulnerability from cvelistv5 – Published: 2026-07-07 23:55 – Updated: 2026-07-08 13:10

Title

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

Summary

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.

Severity

8.3 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-08 13:09 UTC

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')

Assigner

GitHub_M mitre root

References

6 references

URL	Tags
https://github.com/coder/coder/security/advisorie…	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

Impacted products

1 product

Vendor	Product	Version
coder	coder	Affected: >= 2.34.0, < 2.34.2 Affected: >= 2.33.0, < 2.33.8 Affected: >= 2.30.0, < 2.32.7 Affected: < 2.29.17

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55427",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T13:09:33.858876Z",
                "version": "2.0.3"
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          "shortName": "CISA-ADP"
        },
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      }
    ],
    "cna": {
      "affected": [
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          "product": "coder",
          "vendor": "coder",
          "versions": [
            {
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "\u003c 2.29.17"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s `~/.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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.3,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
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            "scope": "CHANGED",
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      "problemTypes": [
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        {
          "descriptions": [
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          "tags": [
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          "url": "https://github.com/coder/coder/releases/tag/v2.32.7"
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      "title": "Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`"
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-MCQQ-FQGF-RXWM

Summary

Impact

Patches

Workarounds

Resources

Credits

CVE-2026-55427 (GCVE-0-2026-55427)

Tags

Sightings

Nomenclature

Related by attack behaviour