CVE-2026-43021

Local service interruption via Bluetooth queue leaks

Published May 1, 2026 · Updated May 1, 2026

Memory leaks in Linux Kernel 6.19 through 6.19.11 allow local users to exhaust kernel memory through Bluetooth HCI queue failures. The hci_le_read_remote_features, hci_acl_change_pkt_type, and hci_le_set_phy paths pass a held connection or allocated buffers to hci_cmd_sync_queue_once but do not release them when queuing returns an error and no destroy callback runs. Reachability requires local low-privileged access and an HCI queue error in an affected Bluetooth path; the record does not specify whether exhaustion ends in a hang or crash.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leaks in Linux Kernel 6.19 through 6.19.11 allow local users to exhaust kernel memory through Bluetooth HCI queue failures. The hci_le_read_remote_features, hci_acl_change_pkt_type, and hci_le_set_phy paths pass a held connection or allocated buffers to hci_cmd_sync_queue_once but do not release them when queuing returns an error and no destroy callback runs. Reachability requires local low-privileged access and an HCI queue error in an affected Bluetooth path; the record does not specify whether exhaustion ends in a hang or crash.

The record

CVE
CVE-2026-43021
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7fd74178d4b16dcf47179da634ea9d7c02e3608b
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aca377208e7f7322bf4e107cdec6e7d7e8aa7a88

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7fd74178d4b16dcf47179da634ea9d7c02e3608b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aca377208e7f7322bf4e107cdec6e7d7e8aa7a88

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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