CVE-2026-63750: DoS (CVSS 5.3)

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.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0025

Probability of exploitation

0.16%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

References

Other References

https://github.com/surrealdb/surrealdb/security/advisories/GHSA-65rj-r9fh-jp2v https://www.vulncheck.com/advisories/surrealdb-before-memory-amplification-via-sql-websocket

Frequently Asked Questions

What is 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. Attackers can stream WebSocket frames larger than the configured limit across multiple concurrent connections to consume excessive memory and degrade /sql availability. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-63750? +

CVE-2026-63750 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0025, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-63750? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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