# CVE-2026-47213: BoxLite: Timeout Bypass Vulnerability

> Malicious code in Boxlite sandboxes can bypass timeouts by catching SIGALRM, causing resource exhaustion and service unavailability.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Jun 2026
- **Updated:** 11 Jun 2026
- **Also known as:** GHSA-xjhv-pp2r-6f82, PYSEC-2026-2400

## 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 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-47213?

3 open source packages ship an affected version, including boxlite.


| Package | Ecosystem | 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.

## Is CVE-2026-47213 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47213 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47213 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47213 exists.

Affected packages and fixed versions:
- boxlite (PyPI): affected all versions up to 0.8.2; no fix listed
- boxlite (PyPI): affected all versions up to 0.8.2; no fix listed
- boxlite (PyPI): affected all versions up to 0.8.2; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47213/ (Markdown: https://insights.sbomify.com/CVE-2026-47213/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47213
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47213
- OSV: https://osv.dev/vulnerability/CVE-2026-47213

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47213/
Summaries are generated and may contain mistakes; the official description above is the record.