SurrealDB vulnerable to pre-auth memory amplification via unbounded /sql WebSocket frames

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-63750: 0.49% estimated exploitation activity in the next 30 days; percentile 42.42 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

An anonymous caller could degrade `/sql` availability by streaming WebSocket frames many times larger than the operator-configured per-connection limit. The `/sql` upgrade handler accepted anonymous connections and did not propagate `SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE` to the WebSocket protocol layer — incoming bytes accumulated in the per-connection read buffer before `check_anon` could reject the query, so the memory cost was incurred regardless of whether the caller could ever execute SurrealQL. The same upgrade path also silently ignored `--deny-http sql` and `--deny-arbitrary-query *` for authenticated callers, but that secondary effect does not grant new permissions.

Impact `SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE` is not applied to anonymous `/sql` connections, so each connection can buffer up to the WebSocket library defaults (16 MiB per frame, 64 MiB per reassembled message) of in-flight bytes regardless of the operator's configured limit. Holding this much memory pinned…

Published by the source

1 Jul 2026, 20:15 UTC

Last modified by the source

4 Nov 2026, 02:56 UTC

Source last checked

4 Nov 2026, 06:30 UTC

1. Revision 2 · amended · 4 Nov 2026

   Amended from osv record GHSA-65rj-r9fh-jp2v

2. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-65rj-r9fh-jp2v

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# Patch Next advisory brief: CVE-2026-63750

Advisory: SurrealDB vulnerable to pre-auth memory amplification via unbounded `/sql` WebSocket frames
IDs: CVE-2026-63750, GHSA-65rj-r9fh-jp2v
Record: https://patchnext.com/advisories/ghsa-65rj-r9fh-jp2v (revision 2, source checked 4 Nov 2026, 06:30 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: surrealdb 3.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io surrealdb: affected < 3.1.0; fixed in 3.1.0

## Suggested inspection (read-only)
- crates.io surrealdb: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on surrealdb.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-65rj-r9fh-jp2v (GitHub-reviewed advisory GHSA-65rj-r9fh-jp2v lists affected ranges: crates.io surrealdb >=0 <3.1.0)
- Verified: https://osv.dev/vulnerability/GHSA-65rj-r9fh-jp2v (OSV record GHSA-65rj-r9fh-jp2v lists affected ranges: crates.io surrealdb >=0 <3.1.0 (fixed))

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