CVE-2026-31666

A flaw was found in the Linux kernel's btrfs filesystem. An incorrect return value in the lookup_extent_data_ref() function can lead to the system believing a lookup succeeded when it did not. This can cause operations to be performed on the wrong extent tree item, potentially resulting in data corruption within the extent tree.

Btrfs extent-data-ref lookup could return wrong success after a leaf split; upstream returns the correct error. Red Hat recommends btrfs users install corrected kernels to avoid metadata mis-decisions.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the btrfs module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.