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SurrealDB vulnerable to Denial of Service due to nested types annotations

Moderate severity GitHub Reviewed Published May 27, 2026 in surrealdb/surrealdb • Updated Jul 1, 2026

Package

cargo surrealdb (Rust)

Affected versions

< 3.1.0

Patched versions

3.1.0

Description

The SurrealDB type/kind parser did not enforce the configured recursion depth limit when parsing nested type annotations. The expression parser already enforced the limit for analogous constructs; the kind parser omitted it. An authenticated attacker could send a query with deeply nested type annotations (e.g., array<option<array<option<...>>>>) and exhaust server memory, crashing the process.

This is an incomplete fix for GHSA-6r8p-hpg7-825g, which addressed the same class of bug in the expression parser but did not cover the kind/type annotation parser code path.

Impact

An authenticated user with query execution privileges can crash a SurrealDB server with a single WebSocket message containing deeply nested type annotations.

Patches

A patch has been introduced that wraps parse_concrete_kind and the OPTION<...> arm of parse_inner_kind with enter_object_recursion!, bounding the recursive cycle parse_concrete_kind → parse_inner_kind → parse_inner_single_kind → parse_concrete_kind at the configured object_recursion_limit (default 100). Regression tests cover both cast and DEFINE FIELD paths.

  • Versions 3.1.0 and later are not affected by this issue.

Workarounds

Restrict the ability of untrusted users to execute arbitrary queries via the --deny-arbitrary-query capability flag for the affected user classes (guest, record, or system). Disabling untrusted access to the WebSocket /rpc endpoint also prevents exploitation; the HTTP /sql endpoint's 1 MiB body limit constrains nesting to a depth where OOM is not feasible.

References

@rowan-baker rowan-baker published to surrealdb/surrealdb May 27, 2026
Published to the GitHub Advisory Database Jul 1, 2026
Reviewed Jul 1, 2026
Last updated Jul 1, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS score

Weaknesses

Uncontrolled Recursion

The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-q8qp-67f9-wr3f

Source code

Credits

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