CVE-2026-98733
Status: ReceivedUnscored—
Severity—Unscored
Exploitation probability0.17 %higher than 6% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Serialize fragmented ISO packet queueing
The fragmented path in hci_queue_iso() calls __skb_queue_tail() without holding conn->data_q.lock. The socket lock serializes senders, but the transmit worker can concurrently remove packets from this queue using skb_dequeue().
After an insertion saves the old tail pointer, hci_sched_iso() can dequeue that packet and pass it to the driver. The driver can free the packet before the insertion resumes and writes to the old tail's next pointer, causing a use-after-free. Concurrent updates can also corrupt the queue.
Read full descriptionShow less
Hold the queue lock across the entire fragment batch, as hci_queue_acl() does, to serialize insertion against dequeue while preserving fragment ordering.
Technical details traces, logs and code from the original report
KASAN reported: BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10 Call Trace: hci_send_iso+0xc7d/0xe10 iso_sock_sendmsg+0x710/0x900 __sys_sendto+0x34a/0x3a0 Allocated by task 86: __alloc_skb+0xdd/0x820 alloc_skb_with_frags+0x7e/0x770 sock_alloc_send_pskb+0x67a/0x820 bt_skb_sendmsg.constprop.0+0xc0/0x6c0 iso_sock_sendmsg+0x44e/0x900 Freed by task 90: kmem_cache_free+0xcb/0x3d0 vhci_read+0x33f/0x4d0 vfs_read+0x177/0xa20
CVSS
NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.17 %
- Percentile among all scored CVEs
- 6
- Score date
- 10/20/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
References
Show 4 references
Raw JSON (NVD)
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{
"id": "CVE-2026-98733",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "26afbd826ee326e63a334c37fd45e82e50a615ec",
"lessThan": "d6d709981208567868c5c01ebd1bec5e5e7fdab0",
"versionType": "git"
},
{
"status": "affected",
"version": "26afbd826ee326e63a334c37fd45e82e50a615ec",
"lessThan": "708cdd203d0bbcf9255fffb2e4c308d5b28851a7",
"versionType": "git"
},
{
"status": "affected",
"version": "26afbd826ee326e63a334c37fd45e82e50a615ec",
"lessThan": "a7161730a3ab3f0a3896000db7ab0284683936e6",
"versionType": "git"
},
{
"status": "affected",
"version": "26afbd826ee326e63a334c37fd45e82e50a615ec",
"lessThan": "1a572db43c057566771b485598ad2e66cb390821",
"versionType": "git"
}
],
"programFiles": [
"net/bluetooth/hci_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bluetooth/hci_core.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:26.900",
"references": [
{
"url": "https://git.kernel.org/stable/c/1a572db43c057566771b485598ad2e66cb390821",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/708cdd203d0bbcf9255fffb2e4c308d5b28851a7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a7161730a3ab3f0a3896000db7ab0284683936e6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d6d709981208567868c5c01ebd1bec5e5e7fdab0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "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 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."
}
],
"lastModified": "2026-10-19T10:19:37.433",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}