VulnerabilityPublished 15 Aug 2026Updated 17 Oct 2026

CVE-2026-72336: Linux kernel · Bluetooth: 6lowpan: hold L2CAP conn across debugfs control

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 6.8.0-147.147 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Low

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1014.14~24.04.1 +25

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-53r8-c46r-w2fg

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-38.38	Fixed in 7.0.0-38.38
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1017.17	Fixed in 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1016.16	Fixed in 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1008.9	Fixed in 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A vendor patch is available and should be applied to affected linux-aws kernel versions. The fix ensures proper reference counting of L2CAP connections during debugfs operations to prevent use-after-free conditions. Users should update to patched kernel versions as listed in the affectedVersions field. No additional mitigation actions are indicated by the vendor advisory.

Description

A use-after-free vulnerability in the Linux kernel's Bluetooth 6LoWPAN subsystem (CVE-2026-72336) was resolved. The flaw involves improper handling of L2CAP connection references during debugfs control operations, leading to potential access of freed memory. This occurs because the protection on the HCI device is dropped before reading connection data, allowing a disconnect or device close to tear down the connection concurrently. The issue was confirmed by a kernel address sanitizer (KASAN) report indicating a slab-use-after-free error. A fix was implemented by ensuring the L2CAP connection reference is held properly while the device is locked and dropped only after the debugfs command completes. The vulnerability affects specific linux-aws kernel versions listed and has a low severity rating. A patch is available from the vendor.

Impact

The vulnerability can cause use-after-free memory access in the Bluetooth 6LoWPAN subsystem of the Linux kernel. This may lead to kernel crashes or undefined behavior when the system accesses freed memory. There is no indication of remote code execution or privilege escalation from the provided data. The severity is rated low, reflecting limited impact beyond potential system instability.

Summary

CVE-2026-72336 is a use-after-free vulnerability in the Linux kernel's Bluetooth 6LoWPAN implementation. The function get_l2cap_conn() looks up an LE hci_conn under device lock but drops the lock before accessing l2cap_data, allowing a race condition where a disconnect or device close can free the connection while it is still in use. This leads to a slab-use-after-free error during lowpan_control_write(). The fix involves taking a reference to the L2CAP connection while the device is locked and releasing it after the debugfs command finishes, preventing the connection from being freed prematurely. The vulnerability was confirmed by KASAN memory error reports. Multiple linux-aws kernel versions are affected. The vendor has released patches to address this issue.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 08:10 UTC

Technical details

References

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