{"id":"CVE-2026-89443","title":"kernel: platform/x86: ISST: Validate level in perf mask ioctls (CVE-2026-89443)","summary":"A flaw was found in the Linux kernel's platform/x86 ISST module. The `isst_if_get_perf_level_mask()` and `isst_if_get_base_freq_mask()` functions fail to validate a user-provided 'level' parameter. A local attacker could exploit this by pr…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-125","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-14","sourceUpdated":"2026-09-14T21:49:29+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89443.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89443.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89443"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532417"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89443"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89443"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89443.mbox"},{"url":"https://git.kernel.org/stable/c/beb22ebf76c0415f22d2d0c3f1ff0627e7ae4a68"},{"url":"https://git.kernel.org/stable/c/1a8bab5ceee1a42a78de12d3d69f67516a20588e"},{"url":"https://git.kernel.org/stable/c/1889a9156553f0692acd57caf15e877baace1a01"},{"url":"https://git.kernel.org/stable/c/d19385624bdfb577db9c94bb8879992fd5e17bcd"},{"url":"https://git.kernel.org/stable/c/80e0d353c86a9a168ad6d213f494796294381538"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00166,"epssPercentile":0.05163,"scores":{"vendor":5.5,"cna":7.1},"ingestedAt":"2026-09-14T15:23:07.453Z","slug":"CVE-2026-89443","body":"## Overview\n\nA flaw was found in the Linux kernel's platform/x86 ISST module. The `isst_if_get_perf_level_mask()` and `isst_if_get_base_freq_mask()` functions fail to validate a user-provided 'level' parameter. A local attacker could exploit this by providing an invalid 'level' value, leading to an out-of-bounds read from the per-level offset table. This could result in information disclosure or a denial of service (DoS).\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89443.json)\n\n**kernel: platform/x86: ISST: Validate level in perf mask ioctls** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-14.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":204111,"id":"CVE-2026-89443","ts":1789490231614,"field":"cvss","old":"7.1","new":"5.5"},{"seq":204110,"id":"CVE-2026-89443","ts":1789490231614,"field":"severity","old":"high","new":"medium"},{"seq":198055,"id":"CVE-2026-89443","ts":1789384321574,"field":"cvss","old":"4.4","new":"7.1"},{"seq":198054,"id":"CVE-2026-89443","ts":1789384321574,"field":"severity","old":"medium","new":"high"},{"seq":183546,"id":"CVE-2026-89443","ts":1789356675830,"field":"cvss","old":"7.1","new":"4.4"},{"seq":183545,"id":"CVE-2026-89443","ts":1789356675830,"field":"severity","old":"high","new":"medium"},{"seq":153226,"id":"CVE-2026-89443","ts":1789285349628,"field":"cvss","old":null,"new":"7.1"},{"seq":153225,"id":"CVE-2026-89443","ts":1789285349628,"field":"severity","old":"none","new":"high"},{"seq":147241,"id":"CVE-2026-89443","ts":1789270203745,"field":"cvss","old":null,"new":"4.4"},{"seq":147240,"id":"CVE-2026-89443","ts":1789270203745,"field":"severity","old":"none","new":"medium"},{"seq":108998,"id":"CVE-2026-89443","ts":1789183729893,"field":"cvss","old":null,"new":"4.4"},{"seq":108997,"id":"CVE-2026-89443","ts":1789183729893,"field":"severity","old":"none","new":"medium"}]}