CVE-2026-121419 PUBLISHED

SurrealDB 3.1.0 before 3.3.0 MCP Session Hijack via BoundSubject Collision

Assigner: VulnCheck
Reserved: 03.11.2026 Published: 03.11.2026 Updated: 03.11.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 8.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS Score: 8.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	Low	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	surrealdb
Product	surrealdb
Versions	Default: unaffected affected from 3.1.0 to 3.3.0 (excl.) Version 3.3.0 is unaffected

CVE-2026-121419 PUBLISHED

SurrealDB 3.1.0 before 3.3.0 MCP Session Hijack via BoundSubject Collision

Metrics

Product Status

Credits

References

Problem Types