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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-98735: Bluetooth: hci_core: Serialize ACL scheduling with channel deletion

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 126714c495bf31a5e71411b8e0b65a685bb5e58d, 4fda8f0abeea9929036446d89a476fb8298abcb0, 51f95ea451f25d7e3f048c0f438f04fa74688aae; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 126714c495bf31a5e71411b8e0b65a685bb5e58d, 4fda8f0abeea9929036446d89a476fb8298abcb0, 51f95ea451f25d7e3f048c0f438f04fa74688aae; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Serialize ACL scheduling with channel deletion hci_chan_sent() selects a channel under RCU but drops the read lock before accessing chan->conn and returning the channel. The ACL and LE schedulers then use its packet queue and update its transmit counters without any protection against channel deletion. After TX selects a channel and releases RCU, a disconnect command timeout on the separate request workqueue can run hci_conn_failed() and l2cap_conn_del(). hci_chan_del() can then unlink the channel, complete synchronize_rcu(), purge its queue and free it before TX resumes. This causes use-after-free both in hci_chan_sent() and in its callers. KASAN reported: BUG: KASAN: slab-use-after-free in hci_chan_sent+0x892/0x9b0 Workqueue: hci0 hci_tx_work Call Trace: hci_chan_sent+0x892/0x9b0 hci_tx_work+0x5e6/0xb70 Allocated by task 91: hci_chan_create+0xe3/0x350 l2cap_conn_add.part.0+0x12/0xa30 l2cap_chan_connect+0x110d/0x1b60 l2cap_sock_connect+0x310/0x530 Freed by task 99: hci_chan_del+0x11f/0x170 l2cap_conn_del+0x4f1/0x800 l2cap_connect_cfm+0x88c/0xd30 hci_conn_failed+0x150/0x250 hci_abort_conn_sync+0x3e3/0x800 hci_cmd_sync_run+0x7e/0xc0 hci_abort_conn+0x105/0x1f0 disconnect_sync+0x157/0x290 hci_cmd_sync_work+0x13c/0x290 Hold the existing device mutex across channel selection and transmission in both schedulers to serialize them with channel teardown. Keep timeout handling outside the critical sections because hci_link_tx_to() acquires the same mutex. This also permits the transmit path to sleep, unlike extending the RCU read-side critical section across packet submission.

—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.3affected
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 126714c495bf31a5e71411b8e0b65a685bb5e58daffected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9affected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 74667f6eb7c12b65c56e02e0f527e4099db4ebfdaffected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 780affacd92977fd9b819bdc4f26a6832cb27fdaaffected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 51f95ea451f25d7e3f048c0f438f04fa74688aaeaffected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 86e9708f9d19a7f1bd5dc9c1652d07707f79f5bdaffected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before 4fda8f0abeea9929036446d89a476fb8298abcb0affected · git
    • 3eff45eaf81780dad25c167bbaafa7d25ae407da and later · before f4845ab191a4f686a5da481fbba90ed73bb693b0affected · git
    • before 3.3not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.10-17.2.10-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-98733Oct 18, 2026 · Bluetooth: hci_core: Serialize fragmented ISO packet queueing
    0Monitor
  • ← EarlierCVE-2026-98734Oct 18, 2026 · Bluetooth: hci_core: Serialize SCO and ISO scheduling with teardown
    0Monitor
  • Later →CVE-2026-98736Oct 18, 2026 · Bluetooth: hci_conn: Lock parent access during enhanced SCO setup
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux126714c495bf31a5e71411b8e0b65a685bb5e58dVendor (CNA)
Linux Linux4fda8f0abeea9929036446d89a476fb8298abcb0Vendor (CNA)
Linux Linux51f95ea451f25d7e3f048c0f438f04fa74688aaeVendor (CNA)
Linux Linux74667f6eb7c12b65c56e02e0f527e4099db4ebfdVendor (CNA)
Linux Linux780affacd92977fd9b819bdc4f26a6832cb27fdaVendor (CNA)
Linux Linux7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9Vendor (CNA)
Linux Linux86e9708f9d19a7f1bd5dc9c1652d07707f79f5bdVendor (CNA)
Linux Linuxf4845ab191a4f686a5da481fbba90ed73bb693b0Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 6, 2026+19 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

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References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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