Race condition in Linux kernel - CVE-2026-89772
Published: September 12, 2026
Vulnerability identifier: #VU149027
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89772
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to corrupt data or cause loss of writes.
The vulnerability exists due to missing write protection in Btrfs folio writeback handling when processing writeback for file-backed folios. A local user can modify a writable memory-mapped file during writeback to corrupt data or cause loss of writes.
The issue can affect partial-folio writeback, inline extents, folios spanning EOF, and compression processing.
Affected software
Linux kernel
How to mitigate CVE-2026-89772
Install security update from vendor's repository.