Vulnerability · Published Sep 27, 2026 · Assigned by VulnCheck
CVE-2026-100833Contrast before 1.23.1 Image Substitution via Policy Generation
Critical 9.6
In plain English
A critical-severity improper input validation in contrast from edgelesssys. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official description
Contrast (edgelesssys/contrast) versions 1.14.0 before 1.23.1 generate runtime policies that fail to detect all container image substitutions. A bad rebase during a Kata Containers update accidentally introduced an `allow_storage` rule that accepts storage entries using the `image_guest_pull` driver without verifying the image digest. An attacker with access to the Kata agent API — for example, a Kubernetes cluster administrator in Contrast's threat model — can therefore substitute a container image with an exploit payload, provided the substituted image satisfies the remaining policy rules, undermining the confidential container's integrity guarantees.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| edgelesssys | contrast | 1.14.0 – before 1.23.1 |
Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
References
- GitHub Security Advisory (GHSA-m2qg-wrxv-h898) vendor-advisory
- VulnCheck Advisory: Contrast before 1.23.1 Image Substitution via Policy Generation third-party-advisory