CVE-2026-64676 Kata Containers: Unauthorized mem-agent ttRPC methods let an untrusted host tamper with confidential-guest memory
An untrusted host can tamper with confidential guest memory management, causing performance degradation and availability issues, if the mem-agent feature is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-64676?
CVE-2026-64676 is a medium-severity missing authorization vulnerability in kata-containers, published on 7 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-64676?
How do I fix CVE-2026-64676?
No fix has been published for CVE-2026-64676 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-64676 being exploited?
There is no known exploitation of CVE-2026-64676 in the wild and no public exploit code.
Sources
Also known as AZL-94685, GHSA-h8jv-63p2-496x.