GHSA-33qf-q99x-wpm8 is a medium-severity (CVSS 5.6) remote code execution vulnerability in homeassistant-cli. A fix is available for homeassistant-cli — see the affected versions and patch details below.
Home Assistant Command-line Interface: Handling of user-supplied Jinja2 templates
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-33qf-q99x-wpm8.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-33qf-q99x-wpm8 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
homeassistant-cliReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Up to 1.0.0 of home-assitant-cli (or hass-cli for short) 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.
E. g., it was possible to render a template with hass-cli template bad-template.j2 --local that contained entries like
{%- set b = environ.__globals__['__builtins__'] -%}
{%- set os = b['__import__']('os') -%}
{%- set bio = b['__import__']('builtins') -%}
...
or other malicious Jinja2 expressions. This can lead to arbitrary code execution on the local machine.
In a two step process an adversary could trick/convince an user to download third-party templates which contain harmful code (e. g., perform data manipulation or establish a remote shell) then to render those templates unchecked/reviewed/verified with --local.
The issue only affect the local machine and not a remote Home Assistant instance. It also requires user interventions.
Patches
1.0.0 uses ImmutableSandboxedEnvironment and restricts the usage of environment variables.
Workarounds
Evaluate the Jninja2 templates manually or tool-based before rendering with hass-cli.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | homeassistant-cli | all versions | 1.0.0pip install --upgrade 'homeassistant-cli==1.0.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for homeassistant-cli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update homeassistant-cli to 1.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-33qf-q99x-wpm8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-33qf-q99x-wpm8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-33qf-q99x-wpm8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-33qf-q99x-wpm8 in your dependencies?
O3 Security finds GHSA-33qf-q99x-wpm8 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.