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NVD / CVE Program· CNA Linux

CVE-2026-74509: Bluetooth: hci_sync: Fix advertising data UAFs

Noroxi assessment

Priority: Monitor (action score 35/100)

  • 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: 0.24% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 5.16, 565971488191bf54a87a417abafab6ad0de72201, 95cdcd8c82a501931fd3ae9b3811b0b6da167e94; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 5.16, 565971488191bf54a87a417abafab6ad0de72201, 95cdcd8c82a501931fd3ae9b3811b0b6da167e94; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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_sync: Fix advertising data UAFs hci_find_adv_instance() returns an adv_info pointer that is valid only while hdev->lock is held. The advertising command-sync paths perform instance lookups without that lock and, in some cases, retain the pointer while waiting for a controller response. An advertising termination event can therefore interleave as follows: hci_cmd_sync_work hci_rx_work hci_find_adv_instance() __hci_cmd_sync_status() wait for controller reply hci_dev_lock() hci_remove_adv_instance() kfree(adv) adv->scan_rsp_changed = false KASAN reported: BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 hci_schedule_adv_instance_sync+0x390/0x4c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 87: hci_add_adv_instance+0x538/0xac0 add_advertising+0x885/0x1160 Freed by task 89: kfree+0x131/0x3c0 hci_remove_adv_instance+0x1d8/0x3b0 hci_le_ext_adv_term_evt+0x17b/0x730 Protect the instance lookup and payload construction in the extended advertising, scan response, and periodic advertising data paths. Snapshot the advertising parameters under hdev->lock, but release the lock before waiting for the controller. Clear advertising-data dirty bits before issuing their commands and restore them after a failure using a fresh lookup. Likewise, update the reported transmit power through a fresh lookup after the parameter command completes. No adv_info pointer then survives an HCI command wait.

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.2% · 16th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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

    • 42fe380baaaccbe635c34ca07b29d19b9ec2498d, 5.17affected
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before 565971488191bf54a87a417abafab6ad0de72201affected · git
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before c4cec575a6d6f7c36808a3a0017b0675968bb06baffected · git
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before 95cdcd8c82a501931fd3ae9b3811b0b6da167e94affected · git
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before eb1d8318764de7216e6dbba29a24d69f7ce51348affected · git
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3affected · git
    • cba6b758711cab946c787f7c15be92cc749b8e1f and later · before cdc36db204ffd97b947d64374cf23a210dc74777affected · git
    • 5.15.210 and later · before 5.16affected · semver
    • before 5.17not affected · semver
    • 6.1.184 and later · up to and including 6.1.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2

+96

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-2026-74507Aug 15, 2026 · Bluetooth: HIDP: validate numbered report payloads
    28Monitor
  • ← EarlierCVE-2026-74508Aug 15, 2026 · Bluetooth: HIDP: reject frames without a transaction header
    35Monitor
  • Later →CVE-2026-74510Aug 15, 2026 · Bluetooth: mgmt: fix UAF in pair command cancellation
    31Monitor

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 Linux5.16Vendor (CNA)
Linux Linux565971488191bf54a87a417abafab6ad0de72201Vendor (CNA)
Linux Linux95cdcd8c82a501931fd3ae9b3811b0b6da167e94Vendor (CNA)
Linux Linuxb16ebdbebd2d37f4cdc590bc3e9db71fe90350a3Vendor (CNA)
Linux Linuxc4cec575a6d6f7c36808a3a0017b0675968bb06bVendor (CNA)
Linux Linuxcdc36db204ffd97b947d64374cf23a210dc74777Vendor (CNA)
Linux Linuxeb1d8318764de7216e6dbba29a24d69f7ce51348Vendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
almalinux:kernel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.107-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.67.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+5

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.

No dated events beyond publication.

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

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. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

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

All records