How severe is CVE-2026-43021?

CVE-2026-43021 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-43021 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43021?

CVE-2026-43021 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-43021?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-43021 have an EU (EUVD) identifier?

Yes. CVE-2026-43021 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26620.

When was CVE-2026-43021 published?

CVE-2026-43021 was published on 2026-05-01 and last updated on 2026-06-17.

CVE-2026-43021

CVE-2026-43021 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26620
Weakness: CWE-401
Affected product: Linux Linux Kernel
Published: 2026-05-01
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails When hci_cmd_sync_queue_once() returns with error, the destroy callback will not be called. Fix leaking references / memory on these failures.

Frequently asked questions

What is CVE-2026-43021?: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails When hci_cmd_sync_queue_once() returns with error, the destroy callback will not be called. Fix leaking references / memory on these failures.
How severe is CVE-2026-43021?: CVE-2026-43021 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-43021 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43021?: CVE-2026-43021 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43021?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43021 have an EU (EUVD) identifier?: Yes. CVE-2026-43021 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26620.
When was CVE-2026-43021 published?: CVE-2026-43021 was published on 2026-05-01 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

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