{"id":"CVE-2026-98733","title":"Bluetooth: hci_core: Serialize fragmented ISO packet queueing","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Serialize fragmented ISO packet queueing\n\nThe fragmented path in hci_queue_iso() calls __skb_queue_tail() without\nholding conn->data_q.lock. The so…","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-416"],"vendor":"Linux","product":"Linux","affected":["Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 545fa70f730eb648a610a2f4b2d270865f77b619","Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < d6d709981208567868c5c01ebd1bec5e5e7fdab0","Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 708cdd203d0bbcf9255fffb2e4c308d5b28851a7","Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < a7161730a3ab3f0a3896000db7ab0284683936e6","Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 1a572db43c057566771b485598ad2e66cb390821","Linux 6.0"],"published":"2026-10-18","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:56:09.003Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98733","references":[{"url":"https://git.kernel.org/stable/c/545fa70f730eb648a610a2f4b2d270865f77b619"},{"url":"https://git.kernel.org/stable/c/d6d709981208567868c5c01ebd1bec5e5e7fdab0"},{"url":"https://git.kernel.org/stable/c/708cdd203d0bbcf9255fffb2e4c308d5b28851a7"},{"url":"https://git.kernel.org/stable/c/a7161730a3ab3f0a3896000db7ab0284683936e6"},{"url":"https://git.kernel.org/stable/c/1a572db43c057566771b485598ad2e66cb390821"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98733.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98733"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555106"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98733"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98733"},{"url":"https://kernelcve.org/list/?q=CVE-2026-98733"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00168,"epssPercentile":0.05969,"ingestedAt":"2026-10-18T16:47:32.505Z","slug":"CVE-2026-98733","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Serialize fragmented ISO packet queueing\n\nThe fragmented path in hci_queue_iso() calls __skb_queue_tail() without\nholding conn->data_q.lock. The socket lock serializes senders, but the\ntransmit worker can concurrently remove packets from this queue using\nskb_dequeue().\n\nAfter an insertion saves the old tail pointer, hci_sched_iso() can dequeue\nthat packet and pass it to the driver. The driver can free the packet\nbefore the insertion resumes and writes to the old tail's next pointer,\ncausing a use-after-free. Concurrent updates can also corrupt the queue.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10\n  Call Trace:\n   hci_send_iso+0xc7d/0xe10\n   iso_sock_sendmsg+0x710/0x900\n   __sys_sendto+0x34a/0x3a0\n\n  Allocated by task 86:\n   __alloc_skb+0xdd/0x820\n   alloc_skb_with_frags+0x7e/0x770\n   sock_alloc_send_pskb+0x67a/0x820\n   bt_skb_sendmsg.constprop.0+0xc0/0x6c0\n   iso_sock_sendmsg+0x44e/0x900\n\n  Freed by task 90:\n   kmem_cache_free+0xcb/0x3d0\n   vhci_read+0x33f/0x4d0\n   vfs_read+0x177/0xa20\n\nHold the queue lock across the entire fragment batch, as hci_queue_acl()\ndoes, to serialize insertion against dequeue while preserving fragment\nordering.\n\n## Affected\n\n- `Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 545fa70f730eb648a610a2f4b2d270865f77b619`\n- `Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < d6d709981208567868c5c01ebd1bec5e5e7fdab0`\n- `Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 708cdd203d0bbcf9255fffb2e4c308d5b28851a7`\n- `Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < a7161730a3ab3f0a3896000db7ab0284683936e6`\n- `Linux >= 26afbd826ee326e63a334c37fd45e82e50a615ec < 1a572db43c057566771b485598ad2e66cb390821`\n- `Linux 6.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98733.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":227100,"id":"CVE-2026-98733","ts":1792585128383,"field":"cvss","old":null,"new":"7"},{"seq":227099,"id":"CVE-2026-98733","ts":1792585128383,"field":"severity","old":"none","new":"high"}]}