CVE-2026-23388

A flaw was found in the Linux kernel's Squashfs component. A local attacker could craft a malicious Squashfs image with a corrupted index look-up table, leading to a negative metadata block offset. This negative offset causes an out-of-bounds access when processing the image, resulting in a general protection fault and a system crash, effectively causing a Denial of Service (DoS).

A kernel crash can occur in Squashfs metadata handling because a corrupted index lookup table can produce a negative metadata block offset. The negative offset is later used by squashfs_read_metadata and can lead to an out of bounds access in squashfs_copy_data which triggers a general protection fault. For the CVSS the PR:L because an attacker typically needs the ability to provide or mount a crafted Squashfs image or otherwise influence the filesystem contents.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module squashfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.