CVE-2026-45858

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the ext4 file system when allocating initialized blocks from a large unwritten extent or splitting an unwritten extent during end I/O. A potential for stale data occurs if an extent needs to be split in the middle. Specifically, when ext4 split extent() attempts to split an extent at a certain point using the EXT4 EXT DATA ENTIRE VALID1 and EXT4 EXT MAY ZEROOUT flags, a temporary lack of space may cause ext4 split extent at() to fail. In this scenario, the system zeroes out a portion of the extent and marks the entire range as written. A subsequent successful split using the EXT4 EXT DATA VALID2 flag can leave a stale written extent, exposing old data.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.