Database/Container, Kubernetes & orchestration

Contrast: node installer writes containerd config world-writable, giving local users node takeover

CVSS 8.5CVE-2026-109358Container, Kubernetes & orchestrationcurated

Impact

The Contrast node installer writes the containerd configuration file mode 0666, so any local unprivileged user on the node can edit it - for instance repointing the runc binary path at something they control. The next container start then executes attacker code with containerd's privileges, which is root on the node. On a shared GPU node that is a full escalation from any foothold with local shell to control over every container scheduled there, including other tenants' workloads and the GPU devices they are using. The irony is that Contrast exists to run confidential workloads, so this undercuts the trust boundary it was deployed to provide.

Who can reach it

A local unprivileged user on a Contrast node - any process or tenant that has landed shell access on the host filesystem. Authentication to the cluster API is not needed.

What to do

Upgrade Contrast to 1.24.1. Versions 1.8.0 through 1.24.0 are affected. Patching alone is not enough on already-installed nodes: check and correct the permissions on the containerd config left behind by the old installer, then restart containerd (a drain on nodes running jobs). Treat any node that had the world-writable config as potentially tampered with and inspect the config contents before trusting it.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-109358 https://github.com/edgelesssys/contrast/security/advisories/GHSA-376m-h37w-4rvq https://www.vulncheck.com/advisories/edgeless-systems-contrast-1.8.0-before-1.24.1-world-writable-containerd-config-privilege-escalation

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.