GHSA-X9QQ-2QH5-8RXF

Vulnerability from github – Published: 2026-07-06 21:08 – Updated: 2026-07-06 21:08
VLAI
Summary
Coder's sub-agent app registration bypasses template port-sharing policy enforcement
Details

Summary

The CreateSubAgent RPC did not validate a requested app sharing level against the template's MaxPortSharingLevel before persisting workspace apps, letting a workspace owner exceed the administrator's configured maximum.

Note: Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls.

Impact

A workspace owner with an agent token could register a sub-agent app as PUBLIC even when the template's MaxPortSharingLevel was owner, exposing the app to unauthenticated users via the wildcard app domain. This affected only deployments using Enterprise port-sharing policy and wildcard app hostnames and required an authenticated workspace owner with an agent token.

Patches

The fix clamps the sub-agent app sharing level to the template's MaxPortSharingLevel.

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

Disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing.

Resources

  • Fix: #26061

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22452) for independently disclosing this issue!

Show details on source website

{
  "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-2026-55432"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-06T21:08:32Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe `CreateSubAgent` RPC did not validate a requested app sharing level against the template\u0027s `MaxPortSharingLevel` before persisting workspace apps, letting a workspace owner exceed the administrator\u0027s configured maximum.\n\n\u003e **Note:** Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls.\n\n### Impact\n\nA workspace owner with an agent token could register a sub-agent app as `PUBLIC` even when the template\u0027s `MaxPortSharingLevel` was `owner`, exposing the app to unauthenticated users via the wildcard app domain. This affected only deployments using Enterprise port-sharing policy and wildcard app hostnames and required an authenticated workspace owner with an agent token.\n\n### Patches\n\nThe fix clamps the sub-agent app sharing level to the template\u0027s `MaxPortSharingLevel`.\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\nDisable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing.\n\n### Resources\n\n- Fix: #26061\n\n### Credits\n\nCoder would like to thank Anthropic\u0027s Security Team (ANT-2026-22452) for independently disclosing this issue!",
  "id": "GHSA-x9qq-2qh5-8rxf",
  "modified": "2026-07-06T21:08:32Z",
  "published": "2026-07-06T21:08:32Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/security/advisories/GHSA-x9qq-2qh5-8rxf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/pull/26061"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/coder/coder"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Coder\u0027s sub-agent app registration bypasses template port-sharing policy enforcement"
}



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