Improper input validation in Linux kernel - CVE-2026-63819
Published: July 21, 2026
Vulnerability identifier: #VU138843
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-2026-63819
CWE-ID: CWE-20
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 input validation in f2fs_get_node_folio_ra() when processing a corrupted f2fs inode during filesystem mount and inode truncation. A local user can supply a crafted corrupted f2fs image to trigger a kernel panic and cause a denial of service.
The issue is triggered by an inconsistent node chain in the inode mapping table where a direct node has the same ino and nid in its footer, leading to a bug check in f2fs_do_truncate_blocks().
Affected software
Linux kernel
How to mitigate CVE-2026-63819
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3