PT-2026-39556 · Go · Github.Com/Edgelesssys/Contrast

Published 2026-04-30 · Updated 2026-04-30

OSV

CVSS v3.1

8.1

High

Base vector

AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Impact

The Kata agent policies generated by the Contrast CLI had an issue in the CopyFile verification, which allowed arbitrary writes to the guest root filesytem. A malicious process on the host with the capability to connect to the Kata agent VSOCK could connect to the agent and issue a series of CopyFile requests to overwrite security-critical files or trick the workload into disclosing sensitive data, which effectively amounts to a full guest takeover.

Patches

This issue has been patched in Contrast v1.19.1.

Note that this fix does not change the fact that host-provided content is generally not trustworthy, as documented.

Workarounds

If upgrading is not possible, users can implement the fix in rego and pass it to contrast generate --policy. The rego-only fix is a bit trickier than the patch, because the data to check is binary. See the references for details.

Resources

• Upstream GHSA: https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc
• Alternative policy-only fix: https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e

Fix

Link Following

Weakness Enumeration

CWE-59

Related Identifiers

GHSA-RH99-WC69-C255

Affected Products

Github.Com/Edgelesssys/Contrast

References · 6

• https://osv.dev/vulnerability/GHSA-rh99-wc69-c255 · Vendor Advisory
• https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc · Note
• https://github.com/edgelesssys/contrast/security/advisories/GHSA-rh99-wc69-c255 · Note
• https://github.com/edgelesssys/contrast/releases/tag/v1.19.1 · Note
• https://github.com/edgelesssys/contrast · Note
• https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e · Note