{"id":"CVE-2026-89502","title":"kernel: ring-buffer: Free cpu_buffer::free_page with subbuf_order (CVE-2026-89502)","summary":"A flaw was found in the Linux kernel's ring-buffer component. When sub-buffers are configured with a specific memory allocation order greater than zero, the system attempts to free a memory page using an incorrect size. This memory managem…","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-763","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","affected":["enterprise_linux 10"],"published":"2026-09-11","updated":"2026-09-16","sourceUpdated":"2026-09-16T04:59:58+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89502.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89502.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89502"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532342"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89502"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89502"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89502.mbox"},{"url":"https://git.kernel.org/stable/c/234b1a72e9706fe20c08c96f4374ec8e83b934cb"},{"url":"https://git.kernel.org/stable/c/77275ccea06eaf297e8e6ac3fc830cb72086379a"},{"url":"https://git.kernel.org/stable/c/81063bbb16c4fcf0136c9117d5e49d3621dd6a1e"},{"url":"https://git.kernel.org/stable/c/8c1ecdcdea738efe0494af908f12c0ae3a97fffa"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.002,"epssPercentile":0.10116,"ingestedAt":"2026-09-14T11:11:19.887Z","slug":"CVE-2026-89502","body":"## Overview\n\nA flaw was found in the Linux kernel's ring-buffer component. When sub-buffers are configured with a specific memory allocation order greater than zero, the system attempts to free a memory page using an incorrect size. This memory management error can lead to memory corruption, potentially allowing a local attacker to escalate privileges or cause a system crash (Denial of Service).\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89502.json)\n\n**kernel: ring-buffer: Free cpu_buffer::free_page with subbuf_order** — rated Low by Red Hat. Released 2026-09-11, updated 2026-09-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\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 Enterprise Linux 9\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":205500,"id":"CVE-2026-89502","ts":1789576722247,"field":"cvss","old":"4.4","new":"5.5"},{"seq":204019,"id":"CVE-2026-89502","ts":1789490231072,"field":"cvss","old":null,"new":"4.4"},{"seq":204018,"id":"CVE-2026-89502","ts":1789490231072,"field":"severity","old":"none","new":"medium"},{"seq":147357,"id":"CVE-2026-89502","ts":1789270210588,"field":"cvss","old":null,"new":"4.4"},{"seq":147356,"id":"CVE-2026-89502","ts":1789270210588,"field":"severity","old":"none","new":"medium"},{"seq":109110,"id":"CVE-2026-89502","ts":1789183730342,"field":"cvss","old":null,"new":"4.4"},{"seq":109109,"id":"CVE-2026-89502","ts":1789183730342,"field":"severity","old":"none","new":"medium"}]}