{"id":"CVE-2026-89571","title":"kernel: cxl/features: bound fwctl command payload to the input buffer (CVE-2026-89571)","summary":"A flaw was found in the Linux kernel's CXL (Compute Express Link) features. A local attacker could exploit an out-of-bounds read vulnerability in the `fwctl_cmd_rpc()` and `cxlctl_set_feature()` functions. This occurs when the system attem…","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 OpenShift Container Platform 4","affected":["openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-18","sourceUpdated":"2026-09-18T22:07:25+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89571.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89571.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89571"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532280"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89571"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89571"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89571.mbox"},{"url":"https://git.kernel.org/stable/c/14d52c15d5d99477b20a2d61fe36f347080da6cd"},{"url":"https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17"},{"url":"https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00124,"epssPercentile":0.02438,"scores":{"vendor":4.4,"cna":7.1},"ingestedAt":"2026-09-14T15:23:07.474Z","slug":"CVE-2026-89571","body":"## Overview\n\nA flaw was found in the Linux kernel's CXL (Compute Express Link) features. A local attacker could exploit an out-of-bounds read vulnerability in the `fwctl_cmd_rpc()` and `cxlctl_set_feature()` functions. This occurs when the system attempts to copy data with a small input buffer length but processes a larger, user-controlled operation size without proper validation. This can lead to reading beyond the allocated memory, causing a kernel crash and resulting in a denial of service.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89571.json)\n\n**kernel: cxl/features: bound fwctl command payload to the input buffer** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.\n\nNot affected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nRefer to the advisory for fix availability.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":208097,"id":"CVE-2026-89571","ts":1789922708284,"field":"cvss","old":"4.4","new":"5.5"},{"seq":202877,"id":"CVE-2026-89571","ts":1789403732774,"field":"cvss","old":"7.1","new":"4.4"},{"seq":202876,"id":"CVE-2026-89571","ts":1789403732774,"field":"severity","old":"high","new":"medium"},{"seq":197918,"id":"CVE-2026-89571","ts":1789384320948,"field":"cvss","old":"4.4","new":"7.1"},{"seq":197917,"id":"CVE-2026-89571","ts":1789384320948,"field":"severity","old":"medium","new":"high"},{"seq":183459,"id":"CVE-2026-89571","ts":1789356675452,"field":"cvss","old":"7.1","new":"4.4"},{"seq":183458,"id":"CVE-2026-89571","ts":1789356675452,"field":"severity","old":"high","new":"medium"},{"seq":153386,"id":"CVE-2026-89571","ts":1789285350306,"field":"cvss","old":null,"new":"7.1"},{"seq":153385,"id":"CVE-2026-89571","ts":1789285350306,"field":"severity","old":"none","new":"high"},{"seq":147442,"id":"CVE-2026-89571","ts":1789270210925,"field":"cvss","old":null,"new":"4.4"},{"seq":147441,"id":"CVE-2026-89571","ts":1789270210925,"field":"severity","old":"none","new":"medium"},{"seq":109198,"id":"CVE-2026-89571","ts":1789183730693,"field":"cvss","old":null,"new":"4.4"},{"seq":109197,"id":"CVE-2026-89571","ts":1789183730693,"field":"severity","old":"none","new":"medium"}]}