CVE-2025-54135

Cursor Agent is vulnerable to prompt injection via MCP Special Files

State: Published
Severity: 8.6 High
Published: Aug 5, 2025
Updated: Aug 5, 2025
Reserved: Jul 16, 2025

Description

Cursor is a code editor built for programming with AI. Cursor allows writing in-workspace files with no user approval in versions below 1.3.9, If the file is a dotfile, editing it requires approval but creating a new one doesn't. Hence, if sensitive MCP files, such as the .cursor/mcp.json file don't already exist in the workspace, an attacker can chain a indirect prompt injection vulnerability to hijack the context to write to the settings file and trigger RCE on the victim without user approval. This is fixed in version 1.3.9.

Scores

CVSS	Score	Vector	Source
3.1	8.6 High	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-829 Inclusion of Functionality from Untrusted Control Sphere

Affected Products

Product	Versions
cursorcursor	< 1.3.9Affected

References

https://github.com/cursor/cursor/security/advisories/GHSA-4cxx-hrm3-49rm

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