CVE-2026-31449

A flaw was found in the Linux kernel's ext4 filesystem. A local attacker could exploit this vulnerability by providing a specially crafted or corrupted on-disk extent header. This could cause an out-of-bounds read in memory, potentially leading to information disclosure or a system crash (Denial of Service).

The upstream fix validates p_idx against EXT_LAST_INDEX() before dereferencing extent index entries, returning -EFSCORRUPTED on bad disks. Red Hat considers this primarily relevant to malicious or corrupted ext4 images mounted locally. Errata kernels will carry the patch. Administrators should avoid mounting untrusted ext4 images on sensitive systems until updated.

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 the ext4 module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.