{"api_version":"1","generated_at":"2026-08-08T05:02:55+00:00","cve":"CVE-2026-64676","urls":{"html":"https://cve.report/CVE-2026-64676","api":"https://cve.report/api/cve/CVE-2026-64676.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64676","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64676"},"summary":{"title":"Kata Containers: Unauthorized mem-agent ttRPC methods let an untrusted host tamper with confidential-guest memory","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.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-08-07 22:16:59","updated_at":"2026-08-07 22:16:59"},"problem_types":["CWE-862","CWE-862 CWE-862: Missing Authorization"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"5.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","baseScore":5.7,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"5.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","data":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"LOW","baseScore":5.7,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x","name":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64676","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64676","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"kata-containers","product":"kata-containers","version":"affected < 4.0.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"kata-containers","vendor":"kata-containers","versions":[{"status":"affected","version":"< 4.0.0"}]}],"descriptions":[{"lang":"en","value":"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."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"LOW","baseScore":5.7,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-862","description":"CWE-862: Missing Authorization","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-07T21:47:20.584Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x","tags":["x_refsource_CONFIRM"],"url":"https://github.com/kata-containers/kata-containers/security/advisories/GHSA-h8jv-63p2-496x"}],"source":{"advisory":"GHSA-h8jv-63p2-496x","discovery":"UNKNOWN"},"title":"Kata Containers: Unauthorized mem-agent ttRPC methods let an untrusted host tamper with confidential-guest memory"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-64676","datePublished":"2026-08-07T21:47:20.584Z","dateReserved":"2026-07-20T17:12:12.891Z","dateUpdated":"2026-08-07T21:47:20.584Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-07 22:16:59","lastModifiedDate":"2026-08-07 22:16:59","problem_types":["CWE-862","CWE-862 CWE-862: Missing Authorization"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","baseScore":5.7,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":2.5,"impactScore":2.7}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64676","Ordinal":"1","Title":"Kata Containers: Unauthorized mem-agent ttRPC methods let an unt","CVE":"CVE-2026-64676","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64676","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Kata Containers: Unauthorized mem-agent ttRPC methods let an unt"}]}}}