CVE-2026-117573: masc-ucsc hagent (High, CVSS 8.5)
- CVSS
- 8.5 High (v4.0)
- EPSS
- 0.7% chance of exploitation in the next 30 days (higher than 53% of CVEs)
- Exploited in the wild
- Not on CISA’s KEV list
- Public exploit
- None reported in public exploit databases
- Weakness
- CWE-78
- 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- Published
- Oct 27, 2026
What it is
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.
Description from the National Vulnerability Database.
What to do
Check whether you run masc-ucsc hagent, then apply the vendor’s fix or mitigation from the advisories below.
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.