SurrealDB versions before 1.5.5 (and 2.0.0-beta before 2.0.0-beta.3) allow an attacker to send an arbitrary bincode‑serialized object as credentials in RPC sign‑in or sign‑up operations without proper validation of nested fields. The injected object can contain a subquery that is executed within the database owner's SIGNIN or SIGNUP query under a system session with the editor role, granting the attacker the ability to SELECT, CREATE, UPDATE, and DELETE non‑IAM resources. The attacker cannot view query results directly or affect IAM resources, but can still compromise data integrity and confidentiality for non‑IAM data.

The vulnerability affects the SurrealDB product, specifically all releases prior to version 1.5.5 and prior to 2.0.0‑beta.3. These versions are used in environments where the RPC API is exposed to untrusted users, allowing the subquery injection described above.

With a CVSS score of 8.7, the vulnerability is considered high severity. The EPSS score of less than 1% indicates that the likelihood of exploitation remains low at present, and the vulnerability is not included in the CISA KEV catalog. The attack vector is inferred to be remote, as the exploit requires access to the exposed RPC API and does not require authentication. A successful exploit would allow an unauthenticated attacker to modify or retrieve sensitive non‑IAM data, potentially leading to significant operational damage.