CVE-2026-31447
kernel: ext4: reject mount if bigalloc with s_first_data_block != 0
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 22, 2026
Updated · July 3, 2026
Description
A flaw was found in the ext4 filesystem component of the Linux kernel. This vulnerability occurs when a local user attempts to mount an ext4 filesystem that is configured with bigalloc and a non-zero s_first_data_block value, a configuration that is not supported. The consequence is a Denial of Service (DoS), as the system will reject the mount operation, preventing access to the filesystem.
CVSS score applicability
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.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-1288 · Improper Validation of Consistency within Input