CVE-2026-100838: Contrast before 1.19.1 CopyFile Policy Symlink Subversion

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-27 · updated 2026-10-08
Weakness: CWE-59

Description

Contrast is a confidential-computing runtime for Kubernetes. In versions before 1.19.1, the Kata agent policies generated by the Contrast CLI contained a flaw in the CopyFile verification that allowed arbitrary writes to the guest root filesystem. A malicious process on the untrusted host able to connect to the Kata agent VSOCK could issue a series of CopyFile requests to overwrite security-critical files in the guest or trick the workload into disclosing sensitive data, effectively amounting to a full guest takeover. Users unable to upgrade can apply an equivalent rego policy fix passed to 'contrast generate --policy'.

Affected products

edgelesssys contrast: before 1.19.1 — fixed in 1.19.1

How to fix

Upgrade to a fixed version: edgelesssys contrast 1.19.1. Check the vendor advisory for mitigations.

References

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