SurrealDB CVE-2026-63739

Exploitation requires an authenticated SurrealDB account with the EDITOR or OWNER role and the ability to run DEFINE ANALYZER with a mapper() filter, into which the attacker supplies an arbitrary absolute file path. The vulnerable state is that SURREAL_FILE_ALLOWLIST is empty or not configured - which is the default - so out-of-the-box installations are affected without any special setup. Exploitation is LIMITED by: (1) required privilege - a lower-privilege or unauthenticated user cannot trigger it; (2) output truncation - only the first line of the target file is returned (except for files containing no newlines), so multi-line secrets beyond line one are not directly recoverable; and (3) filesystem reach - only files readable by the OS user the SurrealDB process runs as are accessible, so least-privilege process accounts and container mounts constrain the blast radius. Setting a non-empty allowlist fully neutralizes the condition on affected versions.

The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N, base 8.3) is internally consistent with the description: network-reachable, low complexity, requires low privileges (a legitimate EDITOR/OWNER database account, i.e. authenticated per PR:L), no user interaction, and high confidentiality impact on both the vulnerable system (VC:H) and a subsequent system (SC:H, reflecting that leaked startup credentials/env secrets can escalate toward control of the whole instance). No EPSS score was provided and the CVE is not in CISA KEV, so there is no evidence of active or widespread exploitation - treat exploitation probability as unquantified rather than confirmed-low. No POC was supplied, but the advisory's detail lowers the barrier to weaponization. Practical risk is meaningfully bounded by two factors the raw score understates: the attacker must already hold a privileged EDITOR/OWNER role, and only the first line of any file is disclosed - which nonetheless suffices to read /proc/self/cmdline or /proc/self/environ and recover --user/--pass or secret env vars. Net: a real, prioritize-if-you-run-multi-tenant-SurrealDB issue rather than an internet-wide unauthenticated risk.

An attacker who holds (or compromises) a SurrealDB account with the EDITOR or OWNER role issues a DEFINE ANALYZER statement whose mapper() filter points at /proc/self/environ or /proc/self/cmdline. The resulting parse error returns the first line of that file, disclosing the process's startup root credentials or secret environment variables, which the attacker reuses to take over the instance. No POC is publicly identified, but the attack is low-complexity and network-reachable given a valid privileged account.