How severe is CVE-2026-43359?

CVE-2026-43359 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-2026-43359 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43359?

CVE-2026-43359 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-43359?

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

Does CVE-2026-43359 have an EU (EUVD) identifier?

Yes. CVE-2026-43359 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28665.

When was CVE-2026-43359 published?

CVE-2026-43359 was published on 2026-05-08 and last updated on 2026-06-17.

CVE-2026-43359

CVE-2026-43359 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-191.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-28665
Weakness: CWE-191
Affected product: Linux Linux Kernel
Published: 2026-05-08
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix transaction abort on set received ioctl due to item overflow If the set received ioctl fails due to an item overflow when attempting to add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction since we did some metadata updates before. This means that if a user calls this ioctl with the same received UUID field for a lot of subvolumes, we will hit the overflow, trigger the transaction abort and turn the filesystem into RO mode. A malicious user could exploit this, and this ioctl does not even requires that a user has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume. Fix this by doing an early check for item overflow before starting a transaction. This is also race safe because we are holding the subvol_sem semaphore in exclusive (write) mode. A test case for fstests will follow soon.

Frequently asked questions

What is CVE-2026-43359?: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix transaction abort on set received ioctl due to item overflow If the set received ioctl fails due to an item overflow when attempting to add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction since we did some metadata updates before. This means that if a user calls this ioctl with the same received UUID field for a lot of subvolumes, we will hit the overflow, trigger the transaction abort and turn the filesystem into RO mode. A malicious user could exploit this, and this ioctl does not even requires that a user has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume. Fix this by doing an early check for item overflow before starting a transaction. This is also race safe because we are holding the subvol_sem semaphore in exclusive (write) mode. A test case for fstests will follow soon.
How severe is CVE-2026-43359?: CVE-2026-43359 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-2026-43359 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43359?: CVE-2026-43359 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43359?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43359 have an EU (EUVD) identifier?: Yes. CVE-2026-43359 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28665.
When was CVE-2026-43359 published?: CVE-2026-43359 was published on 2026-05-08 and last updated on 2026-06-17.

References

Affected products (4)

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:*:*:*:*:*:*

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