{"id":"CVE-2026-64676","title":"Kata Containers is an open source implementation of lightweight Virtual Machines (VMs) that perform like containers","summary":"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 managem…","severity":"medium","cvss":5.7,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","cwe":["CWE-862"],"published":"2026-08-07","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:02:22.660","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64676","references":[{"url":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00122,"epssPercentile":0.02314,"ingestedAt":"2026-09-09T21:22:45.525Z","slug":"CVE-2026-64676","body":"## Overview\n\nKata 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":31,"depthScoreParts":{"impact":31.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}