CVE-2026-43209 minix: Add required sanity checking to minix_check_superblock()

What is CVE-2026-43209?

CVE-2026-43209 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Which versions are affected by CVE-2026-43209?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43209?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-43209 being exploited?

There is no known exploitation of CVE-2026-43209 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-43209, DEBIAN-CVE-2026-43209, GHSA-h2vp-f72r-628f, ROOT-OS-DEBIAN-11-CVE-2026-43209, ROOT-OS-UBUNTU-2204-CVE-2026-43209, ROOT-OS-UBUNTU-2404-CVE-2026-43209 and 1 more.