# CVE-2026-96812: Host Root Sandbox Escape in gVisor via Character Device Passthrough and CUSE

> A local attacker with container deployment privileges can escape the gVisor sandbox to execute root code on the host via CUSE device passthrough.

- **Severity:** High 8.8 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-96812, GHSA-3chr-j932-q9pc

## What is CVE-2026-96812?

CVE-2026-96812 is a high-severity vulnerability in Google gVisor, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Exposure of Resource to Wrong Sphere in the host file helper (gofer) in Google gVisor prior to commit 573a9e73cf844f on Linux platforms with CUSE enabled allows a local attacker with container image deployment privileges to achieve root code execution on the host system. By including a /dev/cuse character device node in a container image, opening the device passes through to the host, allowing the sandboxed attacker to register a host device and exploit CUSE unrestricted ioctl handling to overwrite root udev helper memory.

Weakness: CWE-668 (Exposure of Resource to Wrong Sphere), CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2026-96812?


## How do I fix CVE-2026-96812?

No fix has been published for CVE-2026-96812 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-96812 being exploited?

There is no known exploitation of CVE-2026-96812 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96812 and fix it if it is affected.

What it is: CVE-2026-96812 is a high-severity vulnerability in Google gVisor, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-96812 in the wild and no public exploit code.

Affected product: Google gVisor. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-96812/ (Markdown: https://insights.sbomify.com/CVE-2026-96812/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96812
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96812
- OSV: https://osv.dev/vulnerability/CVE-2026-96812

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96812/
Summaries are generated and may contain mistakes; the official description above is the record.