Main Vulnerability Database Vulnerabilities #VU138841

Improper access control in Linux kernel - CVE-2026-63817

Published: July 21, 2026

Vulnerability identifier: #VU138841

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-63817

CWE-ID: CWE-284

Exploitation vector: Local access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper access control in f2fs_iget() meta inode handling when processing a corrupted directory entry with an inode number equal to max_nid while compress_cache is disabled. A local user can create a corrupted directory entry to cause a denial of service.

Only F2FS mounts with compression support present and the compress_cache mount option disabled are affected by this behavior.

Affected software

Linux kernel

How to mitigate CVE-2026-63817

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3

External References

Related Security Bulletins