8.6
HIGH CVSS 4.0
CVE-2026-121419
SurrealDB 3.1.0 before 3.3.0 MCP Session Hijack via BoundSubject Collision
Description

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.

INFO

Published Date :

Nov. 3, 2026, 3:17 p.m.

Last Modified :

Nov. 3, 2026, 3:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-121419 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update SurrealDB to version 3.3.0 or later to fix improper authentication.
  • Update SurrealDB to version 3.3.0 or later.
  • Apply vendor patches for authentication issues.
  • Review and restrict access method permissions.
  • Monitor for unauthorized session activity.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-121419.

URL Resource
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-121419 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-121419 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-121419 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-121419 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Nov. 03, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-269
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121419.json">CVE-2026-121419</a>
    Added Reference https://github.com/surrealdb/surrealdb/security/advisories/GHSA-pgh9-49q4-hqcx
    Added Reference https://www.vulncheck.com/advisories/surrealdb-3.1.0-before-3.3.0-mcp-session-hijack-via-boundsubject-collision
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.