What’s Vulnerable › Vulnerabilities
CVE-2025-54136: Cursor's Modification of MCP Server Definitions Bypasses Manual Re-approvals
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 28.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-08-02 · updated 2026-06-17
- Weakness: CWE-78
Description
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.
Affected products
- cursor: before 1.3 — fixed in 1.3
How to fix
Upgrade to a fixed version: cursor 1.3. Check the vendor advisory for mitigations.
References
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