{"id":"CVE-2026-89448","title":"iommu/vt-d: Force requesting ACS when tboot is enabled","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Force requesting ACS when tboot is enabled\n\nCurrently the conditions of requesting ACS in detect_intel_iommu()\ndon't include tboot, leading to a possible mi…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-358"],"vendor":"Linux","product":"Linux","affected":["Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 579eb867d3da63f3b5e32f235925e1daa7ec70d0","Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < aaeb81241e802c86be69394f72d49fde3f861fbb","Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 45705a6bfdb283f7b3b509010fd617b72f942537","Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 87bc611c6c98a41c00feb7b06b0c297dd141a2ae","Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 607432b2618b61df81134be0ef2562b8300c1216","Linux 2.6.33"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:22:16.872682Z"},"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:46:57.768Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89448","references":[{"url":"https://git.kernel.org/stable/c/579eb867d3da63f3b5e32f235925e1daa7ec70d0"},{"url":"https://git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb"},{"url":"https://git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537"},{"url":"https://git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae"},{"url":"https://git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89448.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89448"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532174"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89448"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89448"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89448.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00142,"epssPercentile":0.03453,"scores":{"cna":9.3,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.453Z","slug":"CVE-2026-89448","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Force requesting ACS when tboot is enabled\n\nCurrently the conditions of requesting ACS in detect_intel_iommu()\ndon't include tboot, leading to a possible misconfiguration with ACS\ndisabled (e.g. due to user opts) while iommu is later forced on by\ntboot_force_iommu().\n\nFix it by checking tboot in detect_intel_iommu().\n\n## Affected\n\n- `Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 579eb867d3da63f3b5e32f235925e1daa7ec70d0`\n- `Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < aaeb81241e802c86be69394f72d49fde3f861fbb`\n- `Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 45705a6bfdb283f7b3b509010fd617b72f942537`\n- `Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 87bc611c6c98a41c00feb7b06b0c297dd141a2ae`\n- `Linux >= 5d990b627537e59a3a2f039ff588a4750e9c1a6a < 607432b2618b61df81134be0ef2562b8300c1216`\n- `Linux 2.6.33`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89448.json)","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":51.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":223317,"id":"CVE-2026-89448","ts":1792180054686,"field":"cvss","old":"7","new":"9.3"},{"seq":223316,"id":"CVE-2026-89448","ts":1792180054686,"field":"severity","old":"high","new":"critical"},{"seq":207002,"id":"CVE-2026-89448","ts":1789749736439,"field":"cvss","old":"9.3","new":"7"},{"seq":207001,"id":"CVE-2026-89448","ts":1789749736439,"field":"severity","old":"critical","new":"high"},{"seq":198053,"id":"CVE-2026-89448","ts":1789384321566,"field":"cvss","old":"4.1","new":"9.3"},{"seq":198052,"id":"CVE-2026-89448","ts":1789384321566,"field":"severity","old":"medium","new":"critical"},{"seq":183544,"id":"CVE-2026-89448","ts":1789356675821,"field":"cvss","old":"9.3","new":"4.1"},{"seq":183543,"id":"CVE-2026-89448","ts":1789356675821,"field":"severity","old":"critical","new":"medium"},{"seq":153230,"id":"CVE-2026-89448","ts":1789285349645,"field":"cvss","old":null,"new":"9.3"},{"seq":153229,"id":"CVE-2026-89448","ts":1789285349645,"field":"severity","old":"none","new":"critical"}]}