# CVE-2026-121423: SurrealDB unbounded recursion in value serialization

Source: https://junglewise.ai/threats/cve-2026-121423-surrealdb-before-3-3-0-contains-an-unbounded-recursion  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-03. Updated: 2026-11-03  
License: CC BY 4.0 with a link back

CVE-2026-121423 · Severity: medium · CVSS 6.5 · Published 2026-11-03

SurrealDB is a multi-tenant database engine. An authenticated user can crash the entire database process—affecting all databases and users on the instance—by creating deeply nested data structures and then querying them, triggering a stack overflow that terminates the process. The poisoned data persists, re-crashing the database on every restart until manually removed.

Technologies: [Surrealdb](https://junglewise.ai/threats/technologies/surrealdb-surrealdb). Vendors: [SurrealDB](https://junglewise.ai/threats/vendors/surrealdb).

## Quick answers

**Is CVE-2026-121423 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121423 being exploited in the wild.

**How severe is CVE-2026-121423?** Medium severity, with a CVSS score of 6.5, published 3 November 2026.

**Which products and versions are affected?** Surrealdb before 3.3.0.

**Is there a fix for CVE-2026-121423?** Yes: fixed in 3.3.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-121423 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-121423?** Check whether you run Surrealdb at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 3.3.0

## Technical details

An unbounded recursion vulnerability exists in three code paths that walk val::Value objects (response serializer, SQL formatter, and storage codec) with no cumulative depth guard. An authenticated user with table write+read privileges can incrementally accumulate depth across multiple shallow UPDATE requests, then trigger stack overflow by reading or exporting the deeply nested value. Because SurrealDB is compiled with panic='abort', the stack overflow unconditionally terminates the surreald process, causing persistent denial of service for all tenants.

## Affected products

- SurrealDB SurrealDB before 3.3.0

## Timeline

- 2026-10-19: disclosed
- 2026-11-03: advisory

## References

- [https://github.com/surrealdb/surrealdb/security/advisories/GHSA-rpmq-gq3f-h6jg](https://github.com/surrealdb/surrealdb/security/advisories/GHSA-rpmq-gq3f-h6jg)
- [https://www.vulncheck.com/advisories/surrealdb-before-3.3.0-dos-via-unbounded-recursion-in-val-value-serialization](https://www.vulncheck.com/advisories/surrealdb-before-3.3.0-dos-via-unbounded-recursion-in-val-value-serialization)

## Related threats

- [SurrealDB server-side request forgery in JWKS URL validation](https://junglewise.ai/threats/cve-2026-121422-surrealdb-from-3-1-0-before-3-3-0-contains-a-server-side-request)
- [SurrealDB server-side request forgery in network deny rules](https://junglewise.ai/threats/cve-2026-121421-surrealdb-3-1-0-before-3-3-0-contains-a-server-side-request)
- [SurrealDB MCP session hijack via BoundSubject fingerprint collision](https://junglewise.ai/threats/cve-2026-121419-surrealdb-from-3-1-0-before-3-3-0-contains-an-improper)
- [SurrealDB authorization bypass via streaming index planner](https://junglewise.ai/threats/cve-2026-121418-surrealdb-from-3-1-0-before-3-3-0-contains-an-incorrect)
- [SurrealDB deny-funcs capability bypass via method-style invocations](https://junglewise.ai/threats/cve-2026-121416-surrealdb-2-0-0-before-3-3-1-does-not-enforce-deny-funcs)