CVE-2026-49258: Nebula Mesh Web UI Lacks Ownership Checks, Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c6v2-3ffm-vcmc",
  "modified" : "2026-06-26T21:29:02Z",
  "published" : "2026-06-26T21:29:02Z",
  "aliases" : [ "CVE-2026-49258" ],
  "summary" : "Nebula Mesh: Web UI lacks ownership checks, enabling cross-operator access to hosts and networks (read, block, delete)",
  "details" : "## Summary\n\nThe web UI (`/ui/*`) does not apply the per-operator CA scoping the JSON API received for GHSA-598g-h2vc-h5vg. Any authenticated non-admin operator (for example, one created via self-registration or OIDC) can access resources belonging to other operators.\n\n## Impact\n\nA non-admin operator can:\n\n- **Block or delete any other operator's host.** `POST /ui/hosts/{id}/block` and `DELETE /ui/hosts/{id}` act on the URL `id` with no ownership check, so a non-admin can block (revoking the host's certificate via the blocklist) or delete any host in the deployment — a cross-operator denial of service.\n- **Read every operator's hosts and networks.** The dashboard, `/ui/hosts`, the host detail page, `/ui/networks` (including the create-form error re-render), and the `/ui/events` stream all return data across all operators, exposing host names, Nebula IPs, public IPs, certificate fingerprints and expiry, and network names and CIDRs.\n\nThis is the same cross-operator class as GHSA-598g; that remediation covered the JSON API but not the web read/mutation surface. The host create/edit/mobile-bundle/network-create paths and all CA-management routes were already correctly scoped.\n\nAffected handlers (`internal/web`): `handleHostDetail`, `handleHostBlock`, `handleHostDelete`, `handleDashboard`, `handlePartialStats`, `handleHosts`, `handleNetworks`, `renderNetworksError`, `handleHostEvents`.\n\n## Conditions\n\nExposure requires at least one non-admin operator to exist (self-registration enabled, OIDC, or an admin-created user). A single-admin deployment with no additional operators is not affected.\n\n## Fix\n\nA complete candidate fix with regression tests is ready in a private repository shared with the maintainer (`ak2k/nebula-mesh-ghsa-web`, PR #1): scope these handlers to the session operator's owned CAs (admins keep the full view), mirroring the API's ownership checks.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/juev/nebula-mesh"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.3.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/juev/nebula-mesh/security/advisories/GHSA-c6v2-3ffm-vcmc"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/juev/nebula-mesh"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639", "CWE-862" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-26T21:29:02Z",
    "nvd_published_at" : null
  }
}