CVE-2026-40602 hass-cli: Handling of user-supplied Jinja2 templates
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-40602?
CVE-2026-40602 is a medium-severity vulnerability in home-assistant-ecosystem home-assistant-cli, published on 21 Apr 2026.
Official description
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.
Which versions are affected by CVE-2026-40602?
3 open source packages ship an affected version, including homeassistant-cli. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
homeassistant-cli PyPI | All versions | 1.0.0 |
homeassistant-cli PyPI | All versions | 1.0.0 |
homeassistant-cli PyPI | All versions | 1.0.0 |
Products include Home-Assistant-Ecosystem Home Assistant Command-Line Interface.
How do I fix CVE-2026-40602?
Upgrade homeassistant-cli to 1.0.0 or later.
Is CVE-2026-40602 being exploited?
There is no known exploitation of CVE-2026-40602 in the wild and no public exploit code.
Sources
Also known as GHSA-33qf-q99x-wpm8, PYSEC-2026-2518.