CVE-2026-63750
SurrealDB versions before 3.1.0 fail to apply the SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE limit to anonymous /sql WebSocket connections, allowing attackers to buffer unbounded frames in the per-connection read buffer.
Does this matter?
Lower severity and a low EPSS score (0.49%). Track it; it rarely justifies an emergency change on its own.
Description
SurrealDB versions before 3.1.0 fail to apply the SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE limit to anonymous /sql WebSocket connections, allowing attackers to buffer unbounded frames in the per-connection read buffer. Attackers can stream WebSocket frames larger than the configured limit across multiple concurrent connections to consume excessive memory and degrade /sql availability.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.49% probability · 41th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- surrealdb/surrealdb
- Source
- disclosure@vulncheck.com
References
- https://github.com/surrealdb/surrealdb/security/advisories/GHSA-65rj-r9fh-jp2vVendor Advisory, Mitigation
- https://www.vulncheck.com/advisories/surrealdb-before-memory-amplification-via-sql-websocketThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.