{"id":"CVE-2026-64676","summary":"Kata Containers: Unauthorized mem-agent ttRPC methods let an untrusted host tamper with confidential-guest memory","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.","aliases":["GHSA-h8jv-63p2-496x"],"modified":"2026-08-09T03:30:18.310978479Z","published":"2026-08-07T21:47:20.584Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-862"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64676.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64676.json"},{"type":"ADVISORY","url":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64676"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/kata-containers/kata-containers","events":[{"introduced":"0"},{"fixed":"cf82bb35c80320178bf7570252fe75d6fb263209"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"4.0.0"}]}}],"versions":["3.32.0","3.31.0","3.30.0","3.29.0","3.28.0","3.27.0","3.26.0","3.25.0","3.24.0","3.23.0","3.22.0","3.21.0","3.20.0","3.19.1","3.19.0","3.18.0","3.17.0","3.16.0","3.15.0","3.14.0","3.13.0","3.12.0","3.11.0","3.10.1","3.10.0","3.9.0","3.8.0","3.7.0","3.6.0","3.5.0","3.4.0","3.3.0-test","3.3.0","3.3.0-alpha0","3.2.0-rc0","3.2.0-alpha4","3.2.0-alpha3","3.2.0-alpha2","3.2.0-alpha1","3.2.0-alpha0","3.1.0-rc0","3.1.0-alpha1","3.1.0-alpha0","3.0.0-rc0","untagged-b5b6198308b02e3a2666","3.0.0-alpha1","3.0.0-alpha0","2.5.0-rc0","2.5.0-alpha2","2.5.0-alpha1","2.5.0-alpha0","2.4.0-rc0","2.4.0-alpha2","2.4.0-alpha1","2.4.0-alpha0","2.3.0-rc0","2.3.0-alpha2","2.3.0-alpha1","2.2.0-rc0","2.3.0-alpha0","2.2.0-alpha1","2.2.0-alpha0","2.1.0-rc0","2.1.0-alpha2","2.1-alpha1","2.1.0-alpha1","2.1.0-alpha0","2.1-alpha0","untagged-c2a61792b39392572d0f","2.0.0-rc0","2.0.0-alpha3","2.0.0-alpha2","2.0.0-alpha1","1.11.0-alpha1","1.11.0-alpha0","1.9.3","1.10.0-rc0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64676.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L"}]}