CVE-2026-47725: Github.com/juev/nebula mesh Nebula-mesh's Web UI Lacks CSRF Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-273q-qgh5-wrj6",
  "modified" : "2026-06-08T23:09:21Z",
  "published" : "2026-06-08T23:09:21Z",
  "aliases" : [ "CVE-2026-47725" ],
  "summary" : "nebula-mesh's web UI lacks CSRF tokens on /ui/* mutating endpoints",
  "details" : "Every `/ui/*` POST / PUT / PATCH / DELETE route processes the request as soon as the session cookie validates. `SameSite=Lax` on the session cookie prevents most cross-site form submits but does not protect:\n\n- top-level form-submit navigations from third-party pages (some browsers still send Lax cookies on top-level POSTs)\n- same-registrable-domain attackers (sibling-subdomain XSS, subdomain takeover)\n- the `GET /ui/logout` route, which a third-party `<img src=\".../ui/logout\">` can force-trigger\n\nThe admin UI signs CA certificates, mints API keys, rotates / retires / deletes CAs, disables operators, and changes server settings. CSRF here is a real privilege escalation, not just annoyance.\n\n## Affected\nAll released versions up to v0.3.2.\n\n## Suggested fix\nDouble-submit cookie: a 32-byte `crypto/rand` token in a non-HttpOnly `_csrf` cookie, echoed in either `X-CSRF-Token` (htmx) or a `_csrf` form field (HTML forms). Compared in constant time. Rotated on every privilege transition (`Login`, OIDC `StartAuthenticatedSession`, `CompleteTwoFactor`, `Logout`) so pre-auth fixation cannot survive promotion. Rejections audit-logged as `ui.csrf.rejected` with reason; response body stays opaque.\n\n`/ui/logout` becomes POST so it is no longer reachable via `<img>` tags.\n\nFix coordinates with the Secure-cookie advisory disclosed concurrently — the `_csrf` cookie inherits the same `Secure`-attribute derivation.\n\n## Reproducer\nWith an authenticated operator session in browser tab A, open the following minimal HTML in any other tab:\n\n```html\n<form action=\"https://nebula.example.com/ui/cas/{ca-id}/delete\" method=\"POST\">\n  <button>Click for free puppy</button>\n</form>\n```\n\nClick. The CA is deleted — the server processes the POST because the session cookie is automatically attached and there is no other check. The same trick works for force-rotate, retire, mint API keys, disable operators, etc.\n\nAlternative force-logout: `<img src=\"https://nebula.example.com/ui/logout\">` placed on an attacker's page logs out any visiting authenticated operator. No interaction required.\n\n## Notes\n- Multipart and JSON endpoints don't exist in the current UI surface. Future additions must rely on the header path because `r.PostFormValue` only reads `application/x-www-form-urlencoded` bodies. The middleware's package comment documents this.\n- The patch assumes nebula-mgmt is the sole authority on its registrable domain. A compromised sibling subdomain can still set parent-domain cookies and forge matches; SameSite=Lax does not prevent that. Documented in the patch.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/juev/nebula-mesh"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.3.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/juev/nebula-mesh/security/advisories/GHSA-273q-qgh5-wrj6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/juev/nebula-mesh"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-269", "CWE-352" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-08T23:09:21Z",
    "nvd_published_at" : null
  }
}