{"id":"AZL-94685","summary":"CVE-2026-64676 affecting package kata-containers-preview 3.27.0~preview2-1","details":"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.","modified":"2026-08-31T05:26:07Z","published":"2026-08-07T22:16:59Z","upstream":["CVE-2026-64676"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64676"}],"affected":[{"package":{"name":"kata-containers-preview","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kata-containers-preview"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.27.0~preview2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-94685.json"}}],"schema_version":"1.9.0"}