CVE-2026-44283: Go.etcd.io/etcd/v3 Etcd RBAC Bypass Allows Unauthorized Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x35m-3gp4-4fh5",
  "modified" : "2026-05-14T20:54:29Z",
  "published" : "2026-05-07T03:21:53Z",
  "aliases" : [ "CVE-2026-44283" ],
  "summary" : "etcd RBAC bypass allows unauthorized data access via PrevKv/lease attachment in nested transaction Put requests",
  "details" : "### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nA vulnerability in etcd allows read access via PrevKv, or lease attachment in Put requests within transaction operations, to bypass RBAC authorization checks. An authenticated user without sufficient read or lease-related permissions may be able to access unauthorized data or attach leases by invoking transaction operations with these features enabled.\n\nKubernetes does not rely on etcd’s built-in authentication and authorization. Instead, the API server handles authentication and authorization itself, so typical Kubernetes deployments are not affected.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\nThis vulnerability is patched in the following versions:\n- etcd 3.6.11\n- etcd 3.5.30\n- etcd 3.4.44\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nIf upgrading is not immediately possible, reduce exposure by treating the affected\nRPCs as unauthenticated in practice.\n\n- restrict network access to etcd server ports so only trusted components can connect\n- require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate\ndistribution\n\n### Reporters\n\nSamy Ghannad (@SamyGhannad on Github) reported that read access via PrevKv in a Put request within etcd transactions bypassed RBAC authorization checks. Benjamin Wang (@ahrtr ) further analyzed that lease attachment in a Put request within etcd transactions also bypassed RBAC authorization checks",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.etcd.io/etcd/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.6.0"
      }, {
        "fixed" : "3.6.11"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.6.10"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.etcd.io/etcd/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.5.0"
      }, {
        "fixed" : "3.5.30"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.5.29"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.etcd.io/etcd"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.4.44"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.4.43"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/etcd-io/etcd/security/advisories/GHSA-x35m-3gp4-4fh5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44283"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/etcd-io/etcd"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-07T03:21:53Z",
    "nvd_published_at" : "2026-05-14T18:16:49Z"
  }
}