Authenticated command execution via non-generic framework bypass
Published May 4, 2026 · Updated May 4, 2026
OS command injection in privsim mcp-test-runner 0.2.0 allows remote authenticated users to execute OS commands through the run_tests MCP tool. For non-generic frameworks, src/index.ts passes the caller-controlled command to child_process.spawn with shell enabled, while validation is limited to the generic branch. Exploitation requires permission to invoke run_tests, and injected commands inherit the server process's filesystem and environment access.
Summary
What happened
OS command injection in privsim mcp-test-runner 0.2.0 allows remote authenticated users to execute OS commands through the run_tests MCP tool. For non-generic frameworks, src/index.ts passes the caller-controlled command to child_process.spawn with shell enabled, while validation is limited to the generic branch. Exploitation requires permission to invoke run_tests, and injected commands inherit the server process's filesystem and environment access.
The record
- CVE
- CVE-2026-7730
- Published
- May 4, 2026
- Updated
- May 4, 2026
- Vendor
- privsim
- Product
- mcp-test-runner
- Classifications
- CWE-77, CWE-78, T1059
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 4, 2026CVE publishedPublication date reported by the CVE source.
- May 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.2.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitHub issue 37 MCP run_tests proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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