CVE-2025-40068

CVE-2025-40068 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: fs: ntfs3: Fix integer overflow in run_unpack() The MFT record relative to the file being opened contains its runlist, an array containing information about the file's location on the physical disk. Analysis of all Call Stack paths showed that the values of the runlist array, from which LCNs are calculated, are not validated before run_unpack function. The run_unpack function decodes the compressed runlist data format from MFT attributes (for example, $DATA), converting them into a runs_tree structure, which describes the mapping of virtual clusters (VCN) to logical clusters (LCN). The NTFS3 subsystem also has a shortcut for deleting files from MFT records - in this case, the RUN_DEALLOCATE command is sent to the run_unpack input, and the function logic provides that all data transferred to the runlist about file or directory is deleted without creating a runs_tree structure. Substituting the runlist in the $DATA attribute of the MFT record for an arbitrary file can lead either to access to arbitrary data on the disk bypassing access checks to them (since the inode access check occurs above) or to destruction of arbitrary data on the disk. Add overflow check for addition operation. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Frequently asked questions

What is CVE-2025-40068?
In the Linux kernel, the following vulnerability has been resolved: fs: ntfs3: Fix integer overflow in run_unpack() The MFT record relative to the file being opened contains its runlist, an array containing information about the file's location on the physical disk. Analysis of all Call Stack paths showed that the values of the runlist array, from which LCNs are calculated, are not validated before run_unpack function. The run_unpack function decodes the compressed runlist data format from MFT attributes (for example, $DATA), converting them into a runs_tree structure, which describes the mapping of virtual clusters (VCN) to logical clusters (LCN). The NTFS3 subsystem also has a shortcut for deleting files from MFT records - in this case, the RUN_DEALLOCATE command is sent to the run_unpack input, and the function logic provides that all data transferred to the runlist about file or directory is deleted without creating a runs_tree structure. Substituting the runlist in the $DATA attribute of the MFT record for an arbitrary file can lead either to access to arbitrary data on the disk bypassing access checks to them (since the inode access check occurs above) or to destruction of arbitrary data on the disk. Add overflow check for addition operation. Found by Linux Verification Center (linuxtesting.org) with SVACE.
Is CVE-2025-40068 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40068?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-40068 have an EU (EUVD) identifier?
Yes. CVE-2025-40068 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-36460.
When was CVE-2025-40068 published?
CVE-2025-40068 was published on 2025-10-28 and last updated on 2026-06-17.

References