{"id":"CVE-2026-98809","title":"kernel: Bluetooth: hci_sync: don't drain cmd_sync backlog on unregister (CVE-2026-98809)","summary":"A flaw was found in the Linux kernel's Bluetooth subsystem. When unregistering a Bluetooth device, pending synchronous commands are processed without reaching the controller, causing each queued request to wait for a full timeout. A local …","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-770","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-23","sourceUpdated":"2026-10-23T17:29:11+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98809.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98809.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98809"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555226"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98809"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98809"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98809.mbox"},{"url":"https://git.kernel.org/stable/c/b11acfcb5925ed27fae692b27931a1ac732677fb"},{"url":"https://git.kernel.org/stable/c/143bde97c4101ae68eb656c87e620c45b07a3090"},{"url":"https://git.kernel.org/stable/c/7f16443a30f4e86d84ae4faf057d333b41ddb757"},{"url":"https://git.kernel.org/stable/c/e8ba8c9c74d1035042cdf6cb5adf8f59b9b1271c"},{"url":"https://git.kernel.org/stable/c/b1f24c1ab52345e810c42a1a81286cb5a7c92252"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00168,"epssPercentile":0.05981,"ingestedAt":"2026-10-18T16:47:32.478Z","slug":"CVE-2026-98809","body":"## Overview\n\nA flaw was found in the Linux kernel's Bluetooth subsystem. When unregistering a Bluetooth device, pending synchronous commands are processed without reaching the controller, causing each queued request to wait for a full timeout. A local user can exploit this issue by queuing an unbounded number of commands, leading to prolonged task hangs and causing 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 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98809.json)\n\n**kernel: Bluetooth: hci_sync: don't drain cmd_sync backlog on unregister** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-23.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\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 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- Red Hat Enterprise Linux 7\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228684,"id":"CVE-2026-98809","ts":1792844905280,"field":"cvss","old":null,"new":"4.4"},{"seq":228683,"id":"CVE-2026-98809","ts":1792844905280,"field":"severity","old":"none","new":"medium"}]}