CVE-2026-63762

SurrealDB before v2.6.1 (and before v3.0.0-beta.3) contains a denial of service vulnerability in its embedded JavaScript scripting engine, which is enabled via the --allow-scripting capability (disabled by default). Any user able to execute arbitrary queries — including unauthenticated guests when --allow-guests is enabled — can use built-in string functions to construct a large string and pass it to the JavaScript runtime for compilation, triggering a null pointer dereference in the underlying QuickJS-NG engine. This causes the server process to terminate immediately without graceful shutdown, requiring a manual restart. The issue was fixed by updating the rquickjs dependency from v0.9.0 to v0.11.0.

SurrealDB before v2.6.1 (and before v3.0.0-beta.3) contains a denial of service vulnerability in its embedded JavaScript scripting engine, which is enabled via the --allow-scripting capability (disabled by default). Any user able to execute arbitrary queries — including unauthenticated guests when --allow-guests is enabled — can use built-in string functions to construct a large string and pass it to the JavaScript runtime for compilation, triggering a null pointer dereference in the underlying QuickJS-NG engine. This causes the server process to terminate immediately without graceful shutdown, requiring a manual restart. The issue was fixed by updating the rquickjs dependency from v0.9.0 to v0.11.0.

SurrealDB before v2.6.1 (and before v3.0.0-beta.3) contains a denial of service vulnerability in its embedded JavaScript scripting engine, which is enabled via the --allow-scripting capability (disabled by default). Any user able to execute arbitrary queries — including unauthenticated guests when --allow-guests is enabled — can use built-in string functions to construct a large string and pass it to the JavaScript runtime for compilation, triggering a null pointer dereference in the underlying QuickJS-NG engine. This causes the server process to terminate immediately without graceful shutdown, requiring a manual restart. The issue was fixed by updating the rquickjs dependency from v0.9.0 to v0.11.0.

In SurrealDB instances with the scripting capability enabled (--allow-scripting), users with the ability to run arbitrary queries can trigger a server crash due to a memory-safety bug in the underlying JS engine. The SurrealDB instance terminates instantly, requiring a manual restart.

The query consists of using built-in string functions to construct a large string and passing it to the JavaScript runtime for compilation. The exact string size required to trigger the crash varies between SurrealDB versions.

Whilst exploiting the vulnerability requires users to be able to run arbitrary queries, if guest access (--allow-guests), is enabled, then guests can perform this attack.

Impact

Any user able to execute queries on a SurrealDB instance with scripting enabled (--allow-scripting) can cause complete denial of service. The server process terminates immediately without graceful shutdown.

The underlying cause of the vulnerability is a null pointer dereference in the QuickJS-NG v0.8 JavaScript engine, this vulnerability cannot be exploited to execute arbitrary code, or compromise the integrity or confidentiality of data.

Patches

Versions prior to SurrealDB v2.6.1 and v3.0.0-beta.3 are vulnerable.

The patches for SurrealDB v2.6.1 and v3.0.0-beta.3 update the rquickjs dependency from v0.9.0 to v0.11.0, which in turn uses an updated version of QuickJS-NG.

Workarounds

Deny execution of embedded scripting functions through the configuration of capabilities by starting SurrealDB with the --deny-scripting flag or the equivalent environment variable SURREAL_CAPS_DENY_SCRIPT=true. This has a usability implication, although scripting functions are disabled by default.

Administrators can also use --deny-arbitrary-query to deny arbitrary querying by either guest, record or system users, or a combination of those, with impacts to functionality for those users.

Links

SurrealDB Documentation - Capabilities SurrealDB Documentation - Guest Access SurrealQL Documentation - Scripting Functions quickjs-ng v0.9 Release Notes https://github.com/surrealdb/surrealdb/pull/6833 https://github.com/surrealdb/surrealdb/pull/6774

SurrealDB before v2.6.1 (and before v3.0.0-beta.3) contains a denial of service vulnerability in its embedded JavaScript scripting engine, which is enabled via the --allow-scripting capability (disabled by default). Any user able to execute arbitrary queries — including unauthenticated guests when --allow-guests is enabled — can use built-in string functions to construct a large string and pass it to the JavaScript runtime for compilation, triggering a null pointer dereference in the underlying QuickJS-NG engine. This causes the server process to terminate immediately without graceful shutdown, requiring a manual restart. The issue was fixed by updating the rquickjs dependency from v0.9.0 to v0.11.0.

SurrealDB before v2.6.1 (and before v3.0.0-beta.3) contains a denial of service vulnerability in its embedded JavaScript scripting engine, which is enabled via the --allow-scripting capability (disabled by default). Any user able to execute arbitrary queries — including unauthenticated guests when --allow-guests is enabled — can use built-in string functions to construct a large string and pass it to the JavaScript runtime for compilation, triggering a null pointer dereference in the underlying QuickJS-NG engine. This causes the server process to terminate immediately without graceful shutdown, requiring a manual restart. The issue was fixed by updating the rquickjs dependency from v0.9.0 to v0.11.0.

In SurrealDB instances with the scripting capability enabled (--allow-scripting), users with the ability to run arbitrary queries can trigger a server crash due to a memory-safety bug in the underlying JS engine. The SurrealDB instance terminates instantly, requiring a manual restart.

The query consists of using built-in string functions to construct a large string and passing it to the JavaScript runtime for compilation. The exact string size required to trigger the crash varies between SurrealDB versions.

Whilst exploiting the vulnerability requires users to be able to run arbitrary queries, if guest access (--allow-guests), is enabled, then guests can perform this attack.

Impact

Any user able to execute queries on a SurrealDB instance with scripting enabled (--allow-scripting) can cause complete denial of service. The server process terminates immediately without graceful shutdown.

The underlying cause of the vulnerability is a null pointer dereference in the QuickJS-NG v0.8 JavaScript engine, this vulnerability cannot be exploited to execute arbitrary code, or compromise the integrity or confidentiality of data.

Patches

Versions prior to SurrealDB v2.6.1 and v3.0.0-beta.3 are vulnerable.

The patches for SurrealDB v2.6.1 and v3.0.0-beta.3 update the rquickjs dependency from v0.9.0 to v0.11.0, which in turn uses an updated version of QuickJS-NG.

Workarounds

Deny execution of embedded scripting functions through the configuration of capabilities by starting SurrealDB with the --deny-scripting flag or the equivalent environment variable SURREAL_CAPS_DENY_SCRIPT=true. This has a usability implication, although scripting functions are disabled by default.

Administrators can also use --deny-arbitrary-query to deny arbitrary querying by either guest, record or system users, or a combination of those, with impacts to functionality for those users.

Links

SurrealDB Documentation - Capabilities SurrealDB Documentation - Guest Access SurrealQL Documentation - Scripting Functions quickjs-ng v0.9 Release Notes https://github.com/surrealdb/surrealdb/pull/6833 https://github.com/surrealdb/surrealdb/pull/6774