Use-after-free in Linux kernel - CVE-2026-31702
Published: May 2, 2026
Vulnerability identifier: #VU128987
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-31702
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in f2fs_compress_write_end_io() when handling compressed writeback completion during a concurrent unmount. A local user can trigger the race condition to cause a denial of service.
The issue occurs in the compressed writeback completion path and requires a race with filesystem unmount activity.
How to mitigate CVE-2026-31702
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/2c97dcb6147c8f7f25c629b93be1e69617de5d4a
- https://git.kernel.org/stable/c/39d4ee19c1e7d753dd655aebee632271b171f43a
- https://git.kernel.org/stable/c/c76cf339b87975ae5b2c06d2d774d5667d25a12a
- https://git.kernel.org/stable/c/ef57cd3329b40c739b9a2e1a8a21ecc4171c6280
- https://git.kernel.org/stable/c/f5154cf3ce1c8193f0c1891d3769f62740cfe6fe