CVE-2026-73423: Astro Composable `astro/hono` Pipeline Bypasses `security.checkOrigin` Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8mv7-9c27-98vc",
  "modified" : "2026-08-12T20:35:36Z",
  "published" : "2026-07-20T23:26:27Z",
  "aliases" : [ "CVE-2026-73423" ],
  "summary" : "Astro: composable `astro/hono` pipeline bypasses `security.checkOrigin` when `middleware()` is absent or misordered",
  "details" : "## Summary\n\nIn the composable `astro/hono` pipeline, the `security.checkOrigin` protection is only installed by the `middleware()` primitive. The `actions()` and `pages()` primitives each dispatch to user code independently, so a pipeline that mounts either primitive before (or without) `middleware()` will bypass the origin check for those requests.\n\n## Details\n\n`security.checkOrigin` (default: `true`) is intended to reject cross-site `POST`/`PUT`/`PATCH`/`DELETE` form submissions. In the classic pipeline (`astro()` all-in-one), the check always runs because Astro injects a virtual middleware module even when the user has no `src/middleware.ts`. In the composable `astro/hono` pipeline, the user assembles primitives manually. The check is only installed inside `middleware()` — so:\n\n- Mounting `actions()` before `middleware()` allows cross-origin form-encoded action requests to execute before the gate runs. The `examples/advanced-routing` example and the Cloudflare `hono` docs shipped this order.\n- Omitting `middleware()` entirely (reasonable for apps with no custom middleware) silently drops `checkOrigin` protection for all on-demand endpoints and pages dispatched through `pages()`.\n\nThe attack is a blind write-only CSRF: the attacker can trigger a state-mutating action or endpoint handler using the victim's cookies, but cannot read the cross-origin response body.\n\n## Affected versions\n\nAstro `>= 7.0.0` when using the composable `astro/hono` pipeline with either:\n- `actions()` mounted before `middleware()`, or\n- `pages()` used without `middleware()`\n\nThe default (non-composable) pipeline is not affected.\n\n## Fix\n\nThe origin check is now applied at each dispatch sink (`ActionHandler.handle` and `PagesHandler.handleWithErrorFallback`), gated on `manifest.checkOrigin`, using the same predicate as the middleware. The check is order-independent and a no-op when `middleware()` has already run.\n\nFix: https://github.com/withastro/astro/pull/17250\n\n## Workaround\n\nEnsure `middleware()` is mounted before both `actions()` and `pages()` in the composable pipeline, and that it is always included even when no custom middleware logic is needed:\n\n```ts\napp.use(middleware());\napp.use(actions());\napp.use(pages());\n```",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "astro"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.0.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/withastro/astro/security/advisories/GHSA-8mv7-9c27-98vc"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/withastro/astro/pull/17250"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/withastro/astro/commit/0b30b35f864310bee8485c952d1877e82e2b9b1a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/withastro/astro"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/withastro/astro/releases/tag/astro@7.0.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-352" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-20T23:26:27Z",
    "nvd_published_at" : null
  }
}