---
id: "CVE-2026-121419"
kind: "vulnerability"
aliases: ["CVE-2026-121419"]
title: "SurrealDB: MCP session fingerprint lets one user hijack another's session"
severity: "high"
cvss: 8.6
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ai-tooling", "mcp", "self-hosted", "surrealdb"]
not_affected_if: ["no-jwt-or-bearer-access", "no-mcp-endpoint", "version-3.3.0-or-later"]
published_at: "2026-11-03T15:17:31+00:00"
first_seen_at: "2026-11-03T15:21:59+00:00"
updated_at: "2026-11-03T15:22:40+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121419", "first_seen_at": "2026-11-03T15:21:59+00:00"}]
---

# SurrealDB: MCP session fingerprint lets one user hijack another's session

SurrealDB versions 3.1.0 before 3.3.0 bind MCP sessions to the access method name instead of the individual user for JWT and Bearer logins. An attacker with any valid low-privilege token for the same access method, plus a victim's mcp-session-id, can run MCP tools with the victim's roles and permissions.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the running SurrealDB version with `surreal version`; affected range is `3.1.0` to before `3.3.0`.
- Look for MCP endpoint use with JWT or Bearer access methods in the SurrealDB configuration.

## Fix

- SurrealDB: move to `3.3.0` or later.

## Timeline

- 2026-11-03T15:21:59+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121419

## Documents

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

## From the sources

SurrealDB from 3.1.0 before 3.3.0 contains an improper authentication vulnerability where the MCP BoundSubject fingerprint uses the access method name instead of per-user identity for JWT/Bearer access. Attackers with a valid low-privilege token for the same access method and a victim's mcp-session-id can hijack the session and execute MCP tools with the victim's roles and permissions.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_