CVE-2026-100833: Edgelesssys Contrast Image Substitution via Runtime Policy Generation (before 1.23.1)
Edgelesssys Contrast versions from 1.14.0 up to before 1.23.1 generate runtime policies that fail to detect all container image substitutions. A faulty allow_storage rule for the image_guest_pull driver does not verify the image digest, so an actor with access to the Kata agent API, such as a cluster administrator in Contrast's threat model, could substitute an image. The CVE is not listed in CISA KEV and no confirmed exploitation appears in the sources consulted.
Overview
Edgelesssys Contrast versions from 1.14.0 up to before 1.23.1 generate runtime policies that do not detect every container image substitution. According to the record, the cause is an allow_storage rule, accidentally introduced during a bad rebase of a Kata Containers update, that accepts storage entries using the image_guest_pull driver without verifying the image digest. The CNA is VulnCheck and the record classifies the issue as CWE-20, Improper Input Validation.
Impact
- The integrity guarantees of confidential containers can be undermined if an image is substituted.
- The record states the substitution must still satisfy the remaining policy rules to succeed.
- The threat model cited in the record assumes an actor with access to the Kata agent API, such as a Kubernetes cluster administrator.
- The CVSS base score from VulnCheck is 9.6 (critical) and the SSVC technical impact is listed as total.
Affected products and versions
- Edgelesssys Contrast from 1.14.0 up to before 1.23.1.
- The record provides no explicit list of fixed versions. The upper boundary of the affected range suggests that 1.23.1 is the first unaffected release, which is an inference from the range data.
Exploitation status
The CISA KEV catalog does not list this CVE in the record, so no active exploitation is confirmed by that source. The SSVC exploitation field is set to none and automatable is set to no. No confirmed exploitation appears in the sources consulted.
Remediation and mitigation
- Identify all deployments of Contrast and check whether the running version falls within the affected range.
- Upgrade to version 1.23.1 or later, consulting the vendor advisory for the authoritative fix guidance.
- Review runtime policies generated by affected versions and regenerate them after upgrading, since policies created earlier may carry the faulty rule.
- Restrict access to the Kata agent API and limit cluster administrative privileges to reduce the set of actors who could tamper with images.
Detection guidance
- Audit storage-related policy rules for entries using the image_guest_pull driver and confirm that image digests are checked.
- Compare the digests of deployed container images with the digests recorded in trusted build or registry metadata.
- Review logs of administrative access to the Kata agent API and to cluster workloads for unexpected changes.
Limitations of the available information
- The record does not describe the exact conditions under which a substituted image would pass the remaining policy rules.
- No explicit fixed version or patch identifier is present in the record's fixes field.
- The EPSS probability is low (0.00234), but this score does not confirm whether exploitation occurs.
- Details of the vendor advisory beyond the record are not included here.
Frequently asked questions
Which versions are affected?
The record lists Edgelesssys Contrast from 1.14.0 up to before 1.23.1 as affected. Versions outside that range are not listed as affected in the record.
Is this vulnerability being exploited in the wild?
The record shows the CVE is not listed in CISA KEV and the SSVC exploitation field is none. No confirmed exploitation appears in the sources consulted.
This analysis was drafted with AI assistance from verified source data and automatically checked against it.