Out-of-bounds write in Linux kernel - CVE-2026-80638
Published: August 28, 2026
Vulnerability identifier: #VU146245
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-2026-80638
CWE-ID: CWE-787
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 an out-of-bounds write in ocfs2_remove_refcount_extent() when unlinking a refcounted file whose refcount tree has leaf blocks. A local user can trigger the vulnerable code path to cause a denial of service.
The issue is detected by a fortify panic when the last leaf block is removed from a refcount tree and the root is converted back to leaf mode.
Affected software
Linux kernel
How to mitigate CVE-2026-80638
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3