How severe is CVE-2026-43209?

CVE-2026-43209 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-2026-43209 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43209?

CVE-2026-43209 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-2026-43209?

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

Does CVE-2026-43209 have an EU (EUVD) identifier?

Yes. CVE-2026-43209 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27770.

When was CVE-2026-43209 published?

CVE-2026-43209 was published on 2026-05-06 and last updated on 2026-06-17.

CVE-2026-43209

CVE-2026-43209 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.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-27770
Affected product: Linux Linux Kernel
Published: 2026-05-06
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: minix: Add required sanity checking to minix_check_superblock() The fs/minix implementation of the minix filesystem does not currently support any other value for s_log_zone_size than 0. This is also the only value supported in util-linux; see mkfs.minix.c line 511. In addition, this patch adds some sanity checking for the other minix superblock fields, and moves the minix_blocks_needed() checks for the zmap and imap also to minix_check_super_block(). This also closes a related syzbot bug report.

Frequently asked questions

What is CVE-2026-43209?: In the Linux kernel, the following vulnerability has been resolved: minix: Add required sanity checking to minix_check_superblock() The fs/minix implementation of the minix filesystem does not currently support any other value for s_log_zone_size than 0. This is also the only value supported in util-linux; see mkfs.minix.c line 511. In addition, this patch adds some sanity checking for the other minix superblock fields, and moves the minix_blocks_needed() checks for the zmap and imap also to minix_check_super_block(). This also closes a related syzbot bug report.
How severe is CVE-2026-43209?: CVE-2026-43209 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-2026-43209 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43209?: CVE-2026-43209 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-2026-43209?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43209 have an EU (EUVD) identifier?: Yes. CVE-2026-43209 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27770.
When was CVE-2026-43209 published?: CVE-2026-43209 was published on 2026-05-06 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:2.6.12:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.12:rc6:*:*:*:*:*:*

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