Vulnerability in Edgelesssys Contrast
CVE-2026-100838
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'.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-rh99-wc69-c255) (vendor-advisory)
- VulnCheck Advisory: Contrast before 1.19.1 CopyFile Policy Symlink Subversion (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100838?
- CVE-2026-100838 is a high-severity vulnerability in Edgelesssys Contrast, classified under Improper Link Resolution Before File Access. CVSS score: 8.1/10. Published 2026-09-27.
- How severe is CVE-2026-100838?
- High severity. CVSS v3 base score is 8.1 out of 10.