SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-100838

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.

HIGH 8.6EPSS 0.22%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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'.

CVSS 4.0
8.6 HIGHCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.22% probability · 13th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-59
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%27 September 2026: 0.22%26 October 2026: 0.22%27 September 202626 October 2026

EPSS moved from 0.2% on 27 September 2026 to 0.2% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.