CVE-2026-96812: Host Root Sandbox Escape in gVisor via Character Device Passthrough and CUSE
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Google gVisorto a version that resolves this vulnerability.Patch 573a9e73cf844f
Event History
Frequently Asked Questions
Which deployments are exposed?
Linux hosts running an affected gVisor version prior to commit 573a9e73cf844f are exposed when CUSE is enabled and the host file helper (gofer) can pass through a /dev/cuse device node supplied in a container image.
What access does an attacker need?
The attacker needs local access with privileges to deploy or control a container image. Exploitation relies on placing a /dev/cuse character device node in that image and opening it from inside the sandbox.
What is the impact after successful exploitation?
A successful attacker can achieve root code execution on the host system by registering a host device through CUSE and abusing unrestricted ioctl handling to overwrite root udev helper memory.
How can I determine whether I may be affected?
Check whether the deployment runs gVisor on Linux at a revision before commit 573a9e73cf844f, whether CUSE is enabled, and whether untrusted or attacker-controlled container images can include and use character device nodes such as /dev/cuse.