Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-90266
Published: September 18, 2026
Vulnerability identifier: #VU151210
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-2026-90266
CWE-ID: CWE-754
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 improper handling of a transient error condition in Btrfs zoned filesystem block-group reclaim when relocating a block group. A local user can initiate operations that trigger block-group reclaim to cause a denial of service.
The condition occurs when over-committed metadata plus zone-unusable bytes exceeds the usable size of a metadata block group.
Affected software
Linux kernel
How to mitigate CVE-2026-90266
Install security update from vendor's repository.