Memory leak in Linux kernel - CVE-2026-89644
Published: September 12, 2026
Vulnerability identifier: #VU149157
CSH Severity: Low
CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89644
CWE-ID: CWE-401
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a resource leak.
The vulnerability exists due to missing release of memory after effective lifetime in btrfs_get_blocks_direct_write() when performing a direct I/O write to a NOCOW range and ordered extent allocation fails. A local user can issue a direct I/O write to a NOCOW range to cause a resource leak.
Affected software
Linux kernel
How to mitigate CVE-2026-89644
Install security update from vendor's repository.