GHSA-66R2-5GWJ-GXM2

Vulnerability from github – Published: 2026-09-04 20:50 – Updated: 2026-09-04 20:50
VLAI
Summary
SurrealDB: Writes in a PERMISSIONS clause bypass table permissions
Details

A PERMISSIONS ... WHERE clause is evaluated with permission enforcement disabled, so it can't recurse into its own checks. But the clause could also contain data-modifying statements, and these ran with enforcement still off — so evaluating a permission check could write to tables the caller cannot write.

For example:

DEFINE TABLE post PERMISSIONS FOR update
    WHERE (CREATE log SET at = time::now()) OR true;

Any user allowed to update a post now also creates a log record, even with no permission on log. The clause is evaluated once per matched record, so one statement can cause several writes.

Impact

Only databases with a PERMISSIONS clause that contains a write are affected; FULL, NONE, and read-only clauses are not.

What an attacker can do:

  • With permission to perform the guarded operation (a low-privileged or record user is enough), write to tables in their own database that their permissions would otherwise forbid, by triggering an operation the clause guards.
  • Cause several writes from a single statement — the clause is evaluated once per matched record.
  • Trigger unintended events, cascades, or data corruption on those tables.

What it can't do:

  • Escape the caller's own namespace and database — a permission clause cannot switch namespace or database.
  • Perform root- or namespace-level actions such as creating users; the caller's role still applies.
  • Read hidden data — this is an integrity issue, not disclosure.

Patches

Permission clauses must now be read-only: defining or importing one that contains a write is rejected, and any write attempted while a clause is evaluated is blocked at runtime, including writes reached through a called function. Read-only clauses are unaffected.

  • Versions 3.2.0 and later are not affected by this issue.

Workarounds

Users unable to patch should consider the following workarounds:

  • Review your PERMISSIONS clauses and remove any containing CREATE, UPDATE, DELETE, RELATE, INSERT, or UPSERT.
  • Limit who can define schema and vet imported data — such a clause must be defined before it can be triggered.

Resources

Acknowledgements

Thank you to sondt99 for reporting this issue.

Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "surrealdb-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-63733"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-04T20:50:40Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "A `PERMISSIONS ... WHERE` clause is evaluated with permission enforcement disabled, so it can\u0027t recurse into its own checks. But the clause could also contain data-modifying statements, and these ran with enforcement still off \u2014 so evaluating a permission check could write to tables the caller cannot write.\n\nFor example:\n\n```surql\nDEFINE TABLE post PERMISSIONS FOR update\n    WHERE (CREATE log SET at = time::now()) OR true;\n```\n\nAny user allowed to update a `post` now also creates a `log` record, even with no permission on `log`. The clause is evaluated once per matched record, so one statement can cause several writes.\n\n### Impact\n\nOnly databases with a `PERMISSIONS` clause that contains a write are affected; `FULL`, `NONE`, and read-only clauses are not.\n\nWhat an attacker **can** do:\n\n- With permission to perform the guarded operation (a low-privileged or record user is enough), write to tables in their own database that their permissions would otherwise forbid, by triggering an operation the clause guards.\n- Cause several writes from a single statement \u2014 the clause is evaluated once per matched record.\n- Trigger unintended events, cascades, or data corruption on those tables.\n\nWhat it **can\u0027t** do:\n\n- Escape the caller\u0027s own namespace and database \u2014 a permission clause cannot switch namespace or database.\n- Perform root- or namespace-level actions such as creating users; the caller\u0027s role still applies.\n- Read hidden data \u2014 this is an integrity issue, not disclosure.\n\n### Patches\n\nPermission clauses must now be read-only: defining or importing one that contains a write is rejected, and any write attempted while a clause is evaluated is blocked at runtime, including writes reached through a called function. Read-only clauses are unaffected.\n\n- Versions 3.2.0 and later are not affected by this issue.\n\n### Workarounds\n\nUsers unable to patch should consider the following workarounds:\n\n- Review your `PERMISSIONS` clauses and remove any containing `CREATE`, `UPDATE`, `DELETE`, `RELATE`, `INSERT`, or `UPSERT`.\n- Limit who can define schema and vet imported data \u2014 such a clause must be defined before it can be triggered.\n\n### Resources\n\n- [DEFINE TABLE \u2026 PERMISSIONS](https://surrealdb.com/docs/surrealql/statements/define/table)\n- [DEFINE FIELD](https://surrealdb.com/docs/surrealql/statements/define/field)\n- `fix(core): reject writes in PERMISSIONS clauses and block writes during permission evaluation` (included in SurrealDB 3.2.0)\n\n### Acknowledgements\n\nThank you to [sondt99](https://github.com/sondt99) for reporting this issue.",
  "id": "GHSA-66r2-5gwj-gxm2",
  "modified": "2026-09-04T20:50:40Z",
  "published": "2026-09-04T20:50:40Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/surrealdb/surrealdb/security/advisories/GHSA-66r2-5gwj-gxm2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63733"
    },
    {
      "type": "WEB",
      "url": "https://github.com/surrealdb/surrealdb/commit/1e4c3d743e1591f14f340cb627e56d98b6bd7fd7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/surrealdb/surrealdb/commit/afea699dfb3c8f274ab36861f8a95f5e98d82f1b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/surrealdb/surrealdb"
    },
    {
      "type": "WEB",
      "url": "https://github.com/surrealdb/surrealdb/releases/tag/v3.2.0"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/surrealdb-before-permissions-bypass-via-permissions-clause"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SurrealDB: Writes in a PERMISSIONS clause bypass table permissions"
}



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