CVE-2026-33997: Github.com/docker/docker Moby Has An Off-by-one Error Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pxq6-2prw-chj9",
  "modified" : "2026-03-31T18:40:21Z",
  "published" : "2026-03-27T17:38:09Z",
  "aliases" : [ "CVE-2026-33997" ],
  "summary" : "Moby has an Off-by-one error in its plugin privilege validation",
  "details" : "## Summary\n\nA security vulnerability has been detected that allows [plugins](https://docs.docker.com/engine/extend/legacy_plugins/) privilege validation to be bypassed during `docker plugin install`. Due to an error in the daemon's privilege comparison logic, the daemon may incorrectly accept a privilege set that differs from the one approved by the user.\n\nPlugins that request exactly one privilege are also affected, because no comparison is performed at all.\n\n## Impact\n\n**If plugins are not in use, there is no impact.**\n\nWhen a plugin is installed, the daemon computes the privileges required by the plugin's configuration and compares them with the privileges approved during installation. A malicious plugin can exploit this bug so that the daemon accepts privileges that differ from what was intended to be approved.\n\nAnyone who depends on the plugin installation approval flow as a meaningful security boundary is potentially impacted.\n\nDepending on the privilege set involved, this may include highly sensitive plugin permissions such as broad device access.\n\n**For consideration: exploitation still requires a plugin to be installed from a malicious source, and Docker plugins are relatively uncommon. Docker Desktop also does not support plugins.**\n\n## Workarounds\n\nIf unable to update immediately:\n- Do not install plugins from untrusted sources\n- Carefully review all privileges requested during `docker plugin install`\n- Restrict access to the Docker daemon to trusted parties, following the principle of least privilege\n- Avoid relying on plugin privilege approval as the only control boundary for sensitive environments\n\n## Credits\n\n- Reported by Cody (c@wormhole.guru, PGP 0x9FA5B73E)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/docker/docker"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 29.3.1"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/moby/moby/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.0-beta.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/moby/moby"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 29.3.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/moby/moby/security/advisories/GHSA-pxq6-2prw-chj9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33997"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/moby/moby/commit/f4d6f25bf0c3fa12d4968320a45685947756a22a"
  }, {
    "type" : "WEB",
    "url" : "https://docs.docker.com/engine/extend/legacy_plugins"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/moby/moby"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/moby/moby/releases/tag/docker-v29.3.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-193" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-27T17:38:09Z",
    "nvd_published_at" : "2026-03-31T03:15:57Z"
  }
}