In the Linux kernel, the CIFS file system had a bug where, during an O_TRUNC open that failed to obtain a cached handle, the inode size was incorrectly set to zero before the server was told to truncate. This caused the local inode size to diverge from the actual file size on the server, potentially leading to data loss or corruption if subsequent file operations relied on the stale size. The flaw effectively undermines the integrity of file metadata during truncate operations, and could be exploited by a local or remote attacker with write access to a CIFS share to force misreported or incomplete data.

All Linux systems running the kernel version that contains the CIFS implementation with the unpatched logic are affected. Since no specific kernel version range is provided in the advisory, any distribution kernel that had not been updated to the commit that fixes the issue is vulnerable. The vendor is the Linux kernel community, the product is the Linux operating system kernel.

No CVSS score is supplied and the EPSS score is unavailable, so a precise severity estimate is not possible from the data. The vulnerability is not listed in the CISA KEV catalog, suggesting there are no publicly known exploited instances yet. However, because the flaw can cause improper truncation and data inconsistency, the risk remains moderate to high for systems that rely on CIFS file operations, especially if O_TRUNC is used on files that are critical to application functionality. Exploitation would likely require local or SMB‑based file operations that trigger the non‑cached handle path.