{"id":"CVE-2026-89587","title":"kernel: ACPI: pfr_update: fix stack buffer overflow in query_capability() (CVE-2026-89587)","summary":"A flaw was found in the Linux kernel's ACPI Platform Firmware Runtime Update (pfr_update) component. The `query_capability()` function, responsible for handling ACPI buffer objects from firmware, performs an unchecked memory copy operation…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-120","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":"2026-09-21","sourceUpdated":"2026-09-21T16:49:16+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89587.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89587.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89587"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532213"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89587"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89587"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89587.mbox"},{"url":"https://git.kernel.org/stable/c/d3af83e327565a9444cebc0db714cb837e493046"},{"url":"https://git.kernel.org/stable/c/c5a31b4e7e37c92550be9a2edf51ca853a4d251a"},{"url":"https://git.kernel.org/stable/c/a2151624b55029dad0ca7efd17fb83a0461c8843"},{"url":"https://git.kernel.org/stable/c/6d4ed2fd022bc862b156e53aae163b61259e1caa"},{"url":"https://git.kernel.org/stable/c/15d2b7f38f95d28652170344f39ee492c55e567c"},{"url":"https://git.kernel.org/stable/c/ced45be0073a8a31b30b4a7f68cd3a15734515de"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00142,"epssPercentile":0.03911,"scores":{"vendor":7,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.451Z","slug":"CVE-2026-89587","body":"## Overview\n\nA flaw was found in the Linux kernel's ACPI Platform Firmware Runtime Update (pfr_update) component. The `query_capability()` function, responsible for handling ACPI buffer objects from firmware, performs an unchecked memory copy operation. If the firmware provides an oversized buffer, a stack buffer overflow occurs, leading to memory corruption. This could allow a local attacker to cause a denial of service or potentially execute arbitrary code.\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 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89587.json)\n\n**kernel: ACPI: pfr_update: fix stack buffer overflow in query_capability()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-21.\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\nAffected","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":208452,"id":"CVE-2026-89587","ts":1790005705131,"field":"cvss","old":"7.8","new":"7"},{"seq":197886,"id":"CVE-2026-89587","ts":1789384320813,"field":"cvss","old":"5.7","new":"7.8"},{"seq":197885,"id":"CVE-2026-89587","ts":1789384320813,"field":"severity","old":"medium","new":"high"},{"seq":183445,"id":"CVE-2026-89587","ts":1789356675397,"field":"cvss","old":"7.8","new":"5.7"},{"seq":183444,"id":"CVE-2026-89587","ts":1789356675397,"field":"severity","old":"high","new":"medium"},{"seq":153406,"id":"CVE-2026-89587","ts":1789285350385,"field":"cvss","old":null,"new":"7.8"},{"seq":153405,"id":"CVE-2026-89587","ts":1789285350385,"field":"severity","old":"none","new":"high"},{"seq":147552,"id":"CVE-2026-89587","ts":1789270211355,"field":"cvss","old":null,"new":"5.7"},{"seq":147551,"id":"CVE-2026-89587","ts":1789270211355,"field":"severity","old":"none","new":"medium"},{"seq":109308,"id":"CVE-2026-89587","ts":1789183731368,"field":"cvss","old":null,"new":"5.7"},{"seq":109307,"id":"CVE-2026-89587","ts":1789183731368,"field":"severity","old":"none","new":"medium"}]}