{"id":"CVE-2026-89655","title":"kernel: ceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock (CVE-2026-89655)","summary":"A flaw was found in the Linux kernel's Ceph file system component. A race condition exists in the `__kick_flushing_caps()` function during the handling of capability messages. This allows a separate process to free a data structure (`cf en…","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-366","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":"2026-09-15","sourceUpdated":"2026-09-15T17:58:57+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89655.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89655.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89655"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532127"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89655"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89655"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89655.mbox"},{"url":"https://git.kernel.org/stable/c/091137821e1fc88f37e15201abf055c9494ddc61"},{"url":"https://git.kernel.org/stable/c/01542430081014d80fc9e70e92d6647432ddb7fc"},{"url":"https://git.kernel.org/stable/c/23eb34a53a53cb1a6dab1eeee830633207ac158d"},{"url":"https://git.kernel.org/stable/c/19f16f04c2b014a7dd214dc1e42557d8530b16f3"},{"url":"https://git.kernel.org/stable/c/2701431aa3cc8b23efe6890182e7b04f5e76fab5"},{"url":"https://git.kernel.org/stable/c/fe46746087b5b9c5bb2d022df6c7819218494ced"},{"url":"https://git.kernel.org/stable/c/2dba24dcd5050be4b7b119e6f0b01f62203b5d26"},{"url":"https://git.kernel.org/stable/c/7af4c4f01305b0935adf6d4301b1ec407025485d"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00704,"epssPercentile":0.51475,"scores":{"vendor":7,"cna":9.8},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89655","body":"## Overview\n\nA flaw was found in the Linux kernel's Ceph file system component. A race condition exists in the `__kick_flushing_caps()` function during the handling of capability messages. This allows a separate process to free a data structure (`cf entry`) while `__kick_flushing_caps()` is still iterating over it. This use-after-free (UAF) vulnerability can lead to system instability, a denial of service (DoS), or potentially privilege escalation for a local attacker.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · 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 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89655.json)\n\n**kernel: ceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.\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":205536,"id":"CVE-2026-89655","ts":1789576724437,"field":"cvss","old":"9.8","new":"7"},{"seq":205535,"id":"CVE-2026-89655","ts":1789576724437,"field":"severity","old":"critical","new":"high"},{"seq":197789,"id":"CVE-2026-89655","ts":1789384318862,"field":"cvss","old":"5.3","new":"9.8"},{"seq":197788,"id":"CVE-2026-89655","ts":1789384318862,"field":"severity","old":"medium","new":"critical"},{"seq":183377,"id":"CVE-2026-89655","ts":1789356675110,"field":"cvss","old":"9.8","new":"5.3"},{"seq":183376,"id":"CVE-2026-89655","ts":1789356675110,"field":"severity","old":"critical","new":"medium"},{"seq":153508,"id":"CVE-2026-89655","ts":1789285351068,"field":"cvss","old":null,"new":"9.8"},{"seq":153507,"id":"CVE-2026-89655","ts":1789285351068,"field":"severity","old":"none","new":"critical"},{"seq":147698,"id":"CVE-2026-89655","ts":1789270211928,"field":"cvss","old":null,"new":"5.3"},{"seq":147697,"id":"CVE-2026-89655","ts":1789270211928,"field":"severity","old":"none","new":"medium"},{"seq":109450,"id":"CVE-2026-89655","ts":1789183731960,"field":"cvss","old":null,"new":"5.3"},{"seq":109449,"id":"CVE-2026-89655","ts":1789183731960,"field":"severity","old":"none","new":"medium"}]}