Summary
SurrealDB: Writes in a PERMISSIONS clause bypass table permissions
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.
Workarounds
Users unable to patch should consider the following workarounds:
- Review your
PERMISSIONSclauses and remove any containingCREATE,UPDATE,DELETE,RELATE,INSERT, orUPSERT. - Limit who can define schema and vet imported data, such a clause must be defined before it can be triggered.
Resources
- DEFINE TABLE … PERMISSIONS
- DEFINE FIELD
fix(core): reject writes in PERMISSIONS clauses and block writes during permission evaluation(included in SurrealDB 3.2.0)
Acknowledgements
Thank you to sondt99 for reporting this issue.
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.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-63733 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.2.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is CVE-2026-63733? CVE-2026-63733 is a medium-severity incorrect authorization vulnerability in surrealdb-core (rust), affecting versions < 3.2.0. It is fixed in 3.2.0. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-63733? CVE-2026-63733 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of surrealdb-core are affected by CVE-2026-63733? surrealdb-core (rust) versions < 3.2.0 is affected.
- Is there a fix for CVE-2026-63733? Yes. CVE-2026-63733 is fixed in 3.2.0. Upgrade to this version or later.
- Is CVE-2026-63733 exploitable, and should I be worried? Whether CVE-2026-63733 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-63733 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-63733? Upgrade
surrealdb-coreto 3.2.0 or later.