MCPoison
A high-severity remote code execution vulnerability in Cursor, the AI-assisted code editor, affects versions 1.2.4 and earlier. The flaw is in Cursor’s handling of previously trusted Model Context Protocol (MCP) server configurations at the project level. After a user approves a benign MCP server, Cursor binds trust to the MCP/plugin identity rather than to the exact approved command content. An attacker who can modify an already trusted MCP configuration file can replace the original harmless command with a malicious one, and Cursor will execute the modified command without presenting a new warning or consent prompt. The vulnerable condition can be triggered by changing the MCP configuration inside a shared GitHub repository on a branch the victim uses, or by locally editing the configuration file on the target system. This enables silent execution of attacker-controlled commands such as calc.exe and, more generally, arbitrary OS command execution.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No valid public exploits. Mallory filtered out 2 candidates as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
29 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A similar vulnerability in Cursor involving automatic execution of workspace configurations through MCP, mentioned for comparison only.
A vulnerability in Cursor where project-level MCP configuration could lead to command execution.
A related vulnerability mentioned as part of a broader pattern of auto-executing workspace configurations in AI coding tools; no technical details are provided in the content.
A previously reported vulnerability in Cursor based on the same MCP STDIO architectural weakness that can enable command execution.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.