CVE-2026-47213 BoxLite: Timeout Bypass Vulnerability
Malicious code in Boxlite sandboxes can bypass timeouts by catching SIGALRM, causing resource exhaustion and service unavailability.
- 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-2026-47213?
CVE-2026-47213 is a medium-severity denial of service vulnerability in boxlite-ai boxlite, published on 10 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Boxlite is a sandbox service that allows users to create lightweight virtual machines (Boxes) and launch OCI containers within them to run untrusted code. In versions 0.8.2 and prior, Boxlite allows users to configure a timeout for services running inside the virtual machine. When the timeout is triggered, Boxlite sends a signal to kill the process. However, instead of using the uncatchable SIGKILL signal, Boxlite uses the catchable SIGALRM signal. Malicious code running inside the sandbox can exploit this vulnerability to continue running after the timeout is triggered, leading to resource exhaustion within the virtual machine and affecting the availability of the Boxlite service. This issue has been patched via commit 28159fc.
Weakness: CWE-404
Which versions are affected by CVE-2026-47213?
3 open source packages ship an affected version, including boxlite.
| Package | Affected | Fixed in |
|---|---|---|
boxlite PyPI | All versions to 0.8.2 | None |
boxlite PyPI | All versions to 0.8.2 | None |
boxlite PyPI | All versions to 0.8.2 | None |
How do I fix CVE-2026-47213?
No fix has been published for CVE-2026-47213 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-47213 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47213 exists.
Sources
Also known as GHSA-xjhv-pp2r-6f82, PYSEC-2026-2400.