CVE-2026-23388 Squashfs: check metadata block offset is within range

What is CVE-2026-23388?

CVE-2026-23388 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 Mar 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:

Squashfs: check metadata block offset is within range

Syzkaller reports a "general protection fault in squashfs_copy_data"

This is ultimately caused by a corrupted index look-up table, which produces a negative metadata block offset.

This is subsequently passed to squashfs_copy_data (via squashfs_read_metadata) where the negative offset causes an out of bounds access.

The fix is to check that the offset is within range in squashfs_read_metadata. This will trap this and other cases.

Weakness: CWE-125

Which versions are affected by CVE-2026-23388?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23388?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-23388 being exploited?

There is no known exploitation of CVE-2026-23388 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 AZL-80601, BELL-CVE-2026-23388, DEBIAN-CVE-2026-23388, GHSA-3667-r4r3-59jh, ROOT-OS-DEBIAN-11-CVE-2026-23388, ROOT-OS-DEBIAN-12-CVE-2026-23388 and 4 more.