Executive brief
Contrast is a tool that generates runtime security policies for confidential containers running on Kata Containers. The vulnerability allows an attacker with access to the Kata agent API (such as a Kubernetes cluster administrator) to substitute a container image with malicious code because the generated policies fail to verify image digests. This undermines the integrity guarantees of confidential containers and could lead to arbitrary code execution within the container environment.
Technical details
The vulnerability stems from an incomplete rebase during a Kata Containers update that introduced an `allow_storage` rule accepting `image_guest_pull` driver entries without verifying image digests. An attacker with Kata agent API access can exploit this by substituting a container image with a payload that satisfies other policy rules. The flaw is in the runtime policy generation logic and affects versions 1.14.0 through 1.23.0; it was fixed in 1.23.1 by properly moving digest verification to the `allow_mount_point` rule.
Affected products
- Edgeless Systems Contrast 1.14.0 through 1.23.0
Timeline
- 2026-08-24: disclosed: GitHub security advisory GHSA-m2qg-wrxv-h898 published
- 2026-09-27: other: NVD entry published as CVE-2026-100833
- 2026-09-27: patched: Patches available in v1.23.1 and v1.24.0