# CVE-2026-121419: SurrealDB MCP session hijack via BoundSubject fingerprint collision

Source: https://junglewise.ai/threats/cve-2026-121419-surrealdb-from-3-1-0-before-3-3-0-contains-an-improper  
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-2026-121419 · Severity: high · CVSS 8.1 · Published 2026-11-03

SurrealDB is a database platform that supports Model Context Protocol (MCP) for executing tools via HTTP. Attackers with a valid low-privilege token can hijack another user's MCP session if they know the victim's session ID, allowing them to execute database operations with the victim's higher privileges and permissions. This enables cross-user account takeover and privilege escalation within MCP sessions.

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

## Quick answers

**Is CVE-2026-121419 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121419 being exploited in the wild.

**How severe is CVE-2026-121419?** High severity, with a CVSS score of 8.1, published 3 November 2026.

**Which products and versions are affected?** Surrealdb 3.1.0 through 3.2.x before 3.3.0.

**Is there a fix for CVE-2026-121419?** 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-2026-121419 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-121419?** 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

The vulnerability lies in the MCP BoundSubject fingerprint comparison for JWT/Bearer access methods, which uses the access method name instead of per-user identity to identify authenticated sessions. This causes all users of the same access method to produce identical fingerprints regardless of their individual roles. An attacker with a valid token and the victim's mcp-session-id can pass the session re-check and execute MCP tools with the victim's bound permissions.

## Affected products

- SurrealDB SurrealDB 3.1.0 through 3.2.x before 3.3.0

## Timeline

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

## References

- [https://github.com/surrealdb/surrealdb/security/advisories/GHSA-pgh9-49q4-hqcx](https://github.com/surrealdb/surrealdb/security/advisories/GHSA-pgh9-49q4-hqcx)
- [https://www.vulncheck.com/advisories/surrealdb-3.1.0-before-3.3.0-mcp-session-hijack-via-boundsubject-collision](https://www.vulncheck.com/advisories/surrealdb-3.1.0-before-3.3.0-mcp-session-hijack-via-boundsubject-collision)

## Related threats

- [SurrealDB unbounded recursion in value serialization](https://junglewise.ai/threats/cve-2026-121423-surrealdb-before-3-3-0-contains-an-unbounded-recursion)
- [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 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)