GHSA-2vg6-77g8-24mp: Better Auth Stale Sessions Persist After User Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2vg6-77g8-24mp",
  "modified" : "2026-07-07T20:56:45Z",
  "published" : "2026-07-07T20:56:45Z",
  "aliases" : [ ],
  "summary" : "Better Auth: Stale sessions persist after user deletion across admin, anonymous, and SCIM flows",
  "details" : "### Am I affected?\n\nUsers are affected if all of the following are true:\n\n- They configure `secondaryStorage` on `betterAuth(...)` (Redis, KV, or any external session cache).\n- `session.storeSessionInDatabase` is left unset or set to `false` (the default).\n- Their application's deployment uses one or more of:\n  - The `admin` plugin and calls `auth.api.removeUser(...)` or `authClient.admin.removeUser(...)`.\n  - The `anonymous` plugin and exposes `/delete-anonymous-user` or relies on the after-link hook to clean up the anonymous user.\n  - The `@better-auth/scim` plugin and exposes `DELETE /scim/v2/Users/:userId`.\n\nIf `storeSessionInDatabase` is `true`, sessions are also written to the database, and the database delete cascades; users are not affected.\n\nFix:\n\n1. Upgrade to `better-auth@<patched-version>` or later (and `@better-auth/scim@<patched-version>` if they use SCIM).\n2. If they cannot upgrade, see workarounds below.\n\n### Summary\n\nWhen `secondaryStorage` is configured and `storeSessionInDatabase` is `false`, three user-deletion endpoints in `better-auth` plus one in `@better-auth/scim` call `internalAdapter.deleteUser(userId)` without first calling `internalAdapter.deleteSessions(userId)`. The deleted user's session payload (which carries a cached user object) remains in secondary storage, and `internalAdapter.findSession(token)` keeps returning it as a valid session until the session TTL elapses (default 7 days).\n\n### Details\n\nThe vulnerable call sites are:\n\n- `admin` plugin's `removeUser` (`packages/better-auth/src/plugins/admin/routes.ts:1463`).\n- `anonymous` plugin's self-delete endpoint (`packages/better-auth/src/plugins/anonymous/index.ts:222`).\n- `anonymous` plugin's after-link hook (`packages/better-auth/src/plugins/anonymous/index.ts:325`).\n- `@better-auth/scim`'s `DELETE /scim/v2/Users/:userId` (`packages/scim/src/routes.ts:1019`).\n\nWorking callers that already do the right thing: the core `/delete-user` self-delete and `/delete-user/callback` (`packages/better-auth/src/api/routes/update-user.ts:551`).\n\nThe fix shape extends each vulnerable caller to invoke `deleteSessions(userId)` before `deleteUser(userId)`. The architectural follow-up centralizes the cleanup inside `deleteUser` itself or introduces a single `deleteUserAndSessions` orchestrator so future callers cannot regress this contract.\n\n### Patches\n\nFixed in `better-auth@<patched-version>` and `@better-auth/scim@<patched-version>`. All four user-deletion call sites now invoke `deleteSessions(userId)` before `deleteUser(userId)` so sessions are evicted from secondary storage at the same time the user row is removed.\n\n### Workarounds\n\nIf users cannot upgrade immediately:\n\n- **Configuration-level**: set `session.storeSessionInDatabase: true`. Subsequent user-delete writes reach the session table and the database cascade removes rows. Increases write volume for high-throughput sessions but eliminates the gap.\n- **Code-level (admin path)**: when calling `auth.api.removeUser`, also call `auth.api.revokeUserSessions({ body: { userId } })`, which uses `deleteSessions` internally.\n- **Code-level (SCIM path)**: wrap their SCIM provider's deprovisioning hook to call `auth.api.revokeUserSessions(...)` after the SCIM DELETE.\n- **Code-level (anonymous path)**: in `onLinkAccount`, explicitly call `internalAdapter.deleteSessions(anonymousUser.user.id)` before allowing the new session to be issued.\n\n### Impact\n\n- **Stale session validity**: a deleted user's existing session cookie continues to authenticate against `getSessionFromCtx` until the session TTL elapses (default 7 days). Within that window, the deleted user retains their pre-existing read and write surface.\n- **SCIM-driven deprovisioning gap**: organizations using SCIM to revoke offboarded employees' access do not, in fact, revoke active sessions. The deleted account remains usable for up to 7 days after deprovisioning.\n\n### Credit\n\nReported by @iruizsalinas.\n\n### Resources\n\n- [CWE-613: Insufficient Session Expiration](https://cwe.mitre.org/data/definitions/613.html)\n- [CWE-672: Operation on a Resource after Expiration or Release](https://cwe.mitre.org/data/definitions/672.html)\n- [CWE-459: Incomplete Cleanup](https://cwe.mitre.org/data/definitions/459.html)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "better-auth"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.3.4"
      }, {
        "fixed" : "1.6.11"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@better-auth/scim"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.6.0"
      }, {
        "fixed" : "1.6.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/better-auth/better-auth/security/advisories/GHSA-2vg6-77g8-24mp"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/better-auth/better-auth"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/better-auth/better-auth/releases/tag/v1.6.11"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-459", "CWE-613", "CWE-672" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-07T20:56:45Z",
    "nvd_published_at" : null
  }
}