Bug 2512687 (CVE-2026-64676) - CVE-2026-64676 github.com/kata-containers/kata-containers: Kata Containers: Untrusted host can degrade confidential-guest performance via authorization bypass
Summary: CVE-2026-64676 github.com/kata-containers/kata-containers: Kata Containers: U...
Keywords:
Status: NEW
Alias: CVE-2026-64676
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-07 22:01 UTC by OSIDB Bzimport
Modified: 2026-09-30 07:42 UTC (History)
15 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-08-07 22:01:16 UTC
Kata Containers is an open source implementation of lightweight Virtual Machines (VMs) that perform like containers. In versions prior to 4.0.0, the kata-agent is vulnerable to an authorization bypass in confidential-guest memory management. In Confidential Containers (CoCo) deployments, the kata-agent enforces an OPA/Rego-based AgentPolicy that must authorize every ttRPC API call, forming the security boundary that prevents an untrusted host from directing the confidential guest. Two ttRPC methods introduced with the mem-agent feature are missing this authorization check, so an untrusted host can invoke them unconditionally regardless of the guest's policy configuration. When mem-agent is enabled (off by default), this lets the host tamper with in-guest memory management by forcing swap, aggressive eviction, or compaction, resulting in attacker-controlled availability and performance degradation of the confidential workload entirely outside the agent-policy boundary. The impact does not include memory disclosure or code execution, and severity is bounded by the precondition that mem-agent must be explicitly enabled. This issue is fixed in version 4.0.0.


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