CVE-2026-63759

SurrealDB before 3.1.0 fails to enforce recursion depth limits in the type/kind parser when processing nested type annotations. Authenticated attackers can send queries with deeply nested type annotations to exhaust server memory and crash the process.

SurrealDB before 3.1.0 fails to enforce recursion depth limits in the type/kind parser when processing nested type annotations. Authenticated attackers can send queries with deeply nested type annotations to exhaust server memory and crash the process.

SurrealDB before 3.1.0 fails to enforce recursion depth limits in the type/kind parser when processing nested type annotations. Authenticated attackers can send queries with deeply nested type annotations to exhaust server memory and crash the process.

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.

SurrealDB before 3.1.0 fails to enforce recursion depth limits in the type/kind parser when processing nested type annotations. Authenticated attackers can send queries with deeply nested type annotations to exhaust server memory and crash the process.

SurrealDB before 3.1.0 fails to enforce recursion depth limits in the type/kind parser when processing nested type annotations. Authenticated attackers can send queries with deeply nested type annotations to exhaust server memory and crash the process.

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.