CVE-2025-54136 HIGH

CVE-2025-54136: Cursor's Modification of MCP Server Definitions Bypasses Manual Re-approvals

Vendor Cursor
Product cursor
Weakness CWE-78
Published August 1, 2025
Last update August 4, 2025

CVSS base score

7.2/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Cursor is a code editor built for programming with AI. In versions 1.2.4 and below, attackers can achieve remote and persistent code execution by modifying an already trusted MCP configuration file inside a shared GitHub repository or editing the file locally on the target's machine. Once a collaborator accepts a harmless MCP, the attacker can silently swap it for a malicious command (e.g., calc.exe) without triggering any warning or re-prompt. If an attacker has write permissions on a user's active branches of a source repository that contains existing MCP servers the user has previously approved, or allows an attacker has arbitrary file-write locally, the attacker can achieve arbitrary code execution. This is fixed in version 1.3.

Key dates

02Disclosure timeline

August 1, 2025 CVE published
August 4, 2025 Record updated