{"id":"CVE-2026-89657","title":"kernel: libceph: validate OSD extent maps before cursor advance (CVE-2026-89657)","summary":"A flaw was found in libceph in the Linux kernel. A malicious or compromised authenticated Ceph Object Storage Device (OSD) peer could send a specially crafted sparse-read reply that lacks proper validation of extent maps. This could cause …","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-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":"2026-09-18","sourceUpdated":"2026-09-18T22:12:40+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89657.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89657.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89657"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532301"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89657"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89657"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89657.mbox"},{"url":"https://git.kernel.org/stable/c/94ae5145c520618802b0a24c047dcd5f05835db8"},{"url":"https://git.kernel.org/stable/c/058ffa81f9440c5b4714685611cf697fd3739ec9"},{"url":"https://git.kernel.org/stable/c/2571b35883268a266554e80d368e67fdfea7fb9d"},{"url":"https://git.kernel.org/stable/c/201db408872ca12cf09e36bf0f560138c3dcfa1c"},{"url":"https://git.kernel.org/stable/c/9ec08b7499a62c6d4afa93d36ab47a43fcad57d1"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00603,"epssPercentile":0.4754,"scores":{"vendor":7,"cna":7.5},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89657","body":"## Overview\n\nA flaw was found in libceph in the Linux kernel. A malicious or compromised authenticated Ceph Object Storage Device (OSD) peer could send a specially crafted sparse-read reply that lacks proper validation of extent maps. This could cause the client to advance its message-data cursor beyond the request buffer, leading to a kernel crash and 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 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89657.json)\n\n**kernel: libceph: validate OSD extent maps before cursor advance** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.\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":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208086,"id":"CVE-2026-89657","ts":1789922706880,"field":"cvss","old":"7.5","new":"7"},{"seq":197787,"id":"CVE-2026-89657","ts":1789384318853,"field":"cvss","old":"5.3","new":"7.5"},{"seq":197786,"id":"CVE-2026-89657","ts":1789384318853,"field":"severity","old":"medium","new":"high"},{"seq":183711,"id":"CVE-2026-89657","ts":1789356677059,"field":"cvss","old":"7.5","new":"5.3"},{"seq":183710,"id":"CVE-2026-89657","ts":1789356677059,"field":"severity","old":"high","new":"medium"},{"seq":153512,"id":"CVE-2026-89657","ts":1789285351093,"field":"cvss","old":null,"new":"7.5"},{"seq":153511,"id":"CVE-2026-89657","ts":1789285351093,"field":"severity","old":"none","new":"high"},{"seq":147404,"id":"CVE-2026-89657","ts":1789270210778,"field":"cvss","old":null,"new":"5.3"},{"seq":147403,"id":"CVE-2026-89657","ts":1789270210778,"field":"severity","old":"none","new":"medium"},{"seq":109156,"id":"CVE-2026-89657","ts":1789183730532,"field":"cvss","old":null,"new":"5.3"},{"seq":109155,"id":"CVE-2026-89657","ts":1789183730532,"field":"severity","old":"none","new":"medium"}]}