CVE-2026-39866 Lawnchair vulnerable to Command Injection via unquoted workflow dispatch input in release_update.yml
Command injection in the release workflow allows arbitrary code execution, requiring a patch to secure the build process.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-39866?
CVE-2026-39866 is a high-severity command injection vulnerability in LawnchairLauncher lawnchair, published on 21 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Lawnchair is a free, open-source home app for Android. Prior to commit fcba413f55dd47f8a3921445252849126c6266b2, command injection in release_update.yml workflow dispatch input allows arbitrary code execution. Commit fcba413f55dd47f8a3921445252849126c6266b2 patches the issue.
Weakness: CWE-77
Which versions are affected by CVE-2026-39866?
It affects 1 product.
Products include Lawnchair Lawnchair.
How do I fix CVE-2026-39866?
No fix has been published for CVE-2026-39866 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-39866 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39866 exists.
Public exploit code: 2 proofs of concept on GitHub.
Sources
Also known as GHSA-9prc-pp2c-3427.