RCE in Home-Assistant-Ecosystem Home-Assistant-Cli

CVE-2026-40602

The Home Assistant Command-line interface (hass-cli) is a command-line tool for Home Assistant. Up to 1.0.0 of home-assitant-cli an unrestricted environment was used to handle Jninja2 templates instead of a sandboxed one. The user-supplied input within Jinja2 templates was rendered locally with no restrictions. This gave users access to Python's internals and extended the scope of templating beyond the intended usage. This vulnerability is fixed in 1.0.0.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.001 (3.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40602: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40602?
CVE-2026-40602 is a medium-severity vulnerability in Home-Assistant-Ecosystem Home-Assistant-Cli, classified under Code Injection. CVSS score: 5.6/10. Published 2026-04-21.
How severe is CVE-2026-40602?
Medium severity. CVSS v3 base score is 5.6 out of 10.