{"id":"CVE-2026-89656","title":"kernel: libceph: reject buckets with mismatched CRUSH ids (CVE-2026-89656)","summary":"A flaw was found in libceph within the Linux kernel. This vulnerability allows a local attacker to craft a malformed CRUSH map, which is used for data placement. By doing so, one data bucket can be made to reuse another bucket's memory wor…","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-787","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-16","sourceUpdated":"2026-09-16T07:46:40+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89656.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89656.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89656"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532365"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89656"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89656"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89656.mbox"},{"url":"https://git.kernel.org/stable/c/ee59040d6ed1a5f8d10d27174b8f32c90ca8e89a"},{"url":"https://git.kernel.org/stable/c/baad5875fdd2f5e248250fc3519bb045d64f1716"},{"url":"https://git.kernel.org/stable/c/4aeb93daadf388e72073abc204312dd364eeb30a"},{"url":"https://git.kernel.org/stable/c/6e5c6ce252b1eccfd41670a5cf95ab44f7ba7022"},{"url":"https://git.kernel.org/stable/c/3516a4131c4e45d62ee4e42e82c36930e8c1fbbd"},{"url":"https://git.kernel.org/stable/c/00562ccd4e88d092b9b851df50fad20442bfeb24"},{"url":"https://git.kernel.org/stable/c/79900d978158b2d80eef952fc41b9e4dc58d7b83"},{"url":"https://git.kernel.org/stable/c/3cde4a8302301679937474a5f7a851394cc1bd11"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00521,"epssPercentile":0.43042,"scores":{"vendor":7,"cna":9.8},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89656","body":"## Overview\n\nA flaw was found in libceph within the Linux kernel. This vulnerability allows a local attacker to craft a malformed CRUSH map, which is used for data placement. By doing so, one data bucket can be made to reuse another bucket's memory workspace, leading to an out-of-bounds write. This memory corruption could result in a denial of service or potentially lead to privilege escalation.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, 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 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89656.json)\n\n**kernel: libceph: reject buckets with mismatched CRUSH ids** — rated Important by Red Hat. Released 2026-09-11, updated 2026-09-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\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\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\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\nNot affected:\n\n- Red Hat Enterprise Linux 6\n\n## Remediation\n\nAffected","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":205481,"id":"CVE-2026-89656","ts":1789576721737,"field":"cvss","old":"9.8","new":"7"},{"seq":205480,"id":"CVE-2026-89656","ts":1789576721737,"field":"severity","old":"critical","new":"high"},{"seq":197795,"id":"CVE-2026-89656","ts":1789384318889,"field":"cvss","old":"5.9","new":"9.8"},{"seq":197794,"id":"CVE-2026-89656","ts":1789384318889,"field":"severity","old":"medium","new":"critical"},{"seq":183717,"id":"CVE-2026-89656","ts":1789356677084,"field":"cvss","old":"9.8","new":"5.9"},{"seq":183716,"id":"CVE-2026-89656","ts":1789356677084,"field":"severity","old":"critical","new":"medium"},{"seq":153510,"id":"CVE-2026-89656","ts":1789285351083,"field":"cvss","old":null,"new":"9.8"},{"seq":153509,"id":"CVE-2026-89656","ts":1789285351083,"field":"severity","old":"none","new":"critical"},{"seq":147317,"id":"CVE-2026-89656","ts":1789270209322,"field":"cvss","old":null,"new":"5.9"},{"seq":147316,"id":"CVE-2026-89656","ts":1789270209322,"field":"severity","old":"none","new":"medium"},{"seq":109070,"id":"CVE-2026-89656","ts":1789183730190,"field":"cvss","old":null,"new":"5.9"},{"seq":109069,"id":"CVE-2026-89656","ts":1789183730190,"field":"severity","old":"none","new":"medium"}]}