Human
Machine
REPRO-2026-00118 MEDIUM
Verified
cve-2026-21518
Feb 21, 2026
What's the vulnerability?
VS Code/GitHub Copilot MCP server definitions in workspace settings could start without workspace trust, enabling command execution via malicious .vscode/settings.json; fixed by adding workspace trust checks and punycode encoding for domain normalization.
Root Cause Analysis
One Command
Verify with pruva-verify
Run the Pruva CLI to automatically fetch and execute the reproduction script.
pruva-verify REPRO-2026-00118 or
pruva-verify CVE-2026-21518 Install:
curl -fsSL https://pruva.dev/install.sh | sh Or Run Manually
1
Download the script
curl -O https://pruva.dev/api/v1/reproductions/REPRO-2026-00118/artifacts/repro/reproduction_steps.sh 2
Make executable
chmod +x reproduction_steps.sh 3
Run the script
./reproduction_steps.sh Run in a VM, container, or disposable environment. This exploits a real vulnerability.
How Pruva Reproduced This
Watch the AI agent's step-by-step process.
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Artifacts
repro/reproduction_steps.sh3.5 KBrepro/rca_report.md2.8 KBbundle/source.json0.8 KBbundle/ticket.json4.0 KBbundle/ticket.md4.2 KBrepro/run_repro.mjs0.8 KBrepro/mcp_workspace_trust_repro.ts10.1 KBlogs/summary.log0.0 KBlogs/variant_patched.log0.2 KBlogs/variant_esbuild_vuln.log0.0 KBlogs/variant_worktree.log0.1 KBlogs/patched_run.log0.1 KBlogs/variant_npm_install.log0.0 KBlogs/vulnerable_run.log0.1 KBlogs/variant_summary.log0.1 KBlogs/variant_esbuild_fixed.log0.0 KBlogs/esbuild.log0.0 KBlogs/variant_vulnerable.log0.2 KBlogs/npm_install.log0.0 KB