Use-after-free in Linux kernel - CVE-2026-93800
Published: September 25, 2026
Vulnerability identifier: #VU152099
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-93800
CWE-ID: CWE-416
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 use-after-free in the btrfs relocation root cleanup logic when handling errors returned by btrfs_update_reloc_root() during relocation. A local user can trigger relocation that encounters an error and unmount the filesystem to cause a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-93800
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3