CVE-2026-89614

CRITICALCVSS 9.8/10EPSS 0.16%

Last modified

CVE-2026-89614 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the free-cluster bitmap scan to the volume vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap. Those are independent on-disk quantities and the mount-time check only rejects a $Bitmap that is too small, so an image whose $Bitmap covers more clusters than the volume has lets the scan index past the array. A run whose LCN lies in that gap takes the allocator straight there, since the caller passes the file's own last LCN as its locality hint. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the free-cluster bitmap scan to the volume vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap. Those are independent on-disk quantities and the mount-time check only rejects a $Bitmap that is too small, so an image whose $Bitmap covers more clusters than the volume has lets the scan index past the array. A run whose LCN lies in that gap takes the allocator straight there, since the caller passes the file's own last LCN as its locality hint. KASAN reports a slab out-of-bounds read when a file on such a volume is extended. Clamp the scan to what that array covers, mirroring the max_index calculation the mount-time scan already uses, and reject a decoded LCN at or beyond nr_clusters in the mapping pairs decoder. Conforming volumes are unaffected.

Metrics

EPSS Probability
0.16%

5.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 11ccc9107dc460de28af90fac1f42404d9802735, < dc15a9f5307d5372aef3b64bf3ed7802f530c471; >= 11ccc9107dc460de28af90fac1f42404d9802735, < 19cac7902a8ab748e15f98ddaafcf5f8882be21d
LinuxLinux7.1

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-89614?
In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the free-cluster bitmap scan to the volume vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap. Those are independent on-disk quantities and the mount-time check only rejects a $Bitmap that is too small, so an image whose $Bitmap covers more clusters than the volume has lets the scan index past the array. A run whose LCN lies in that gap takes the allocator straight there, since the caller passes the file's own last LCN as its locality hint. KASAN reports a slab out-of-bounds read when a file on such a volume is extended. Clamp the scan to what that array covers, mirroring the max_index calculation the mount-time scan already uses, and reject a decoded LCN at or beyond nr_clusters in the mapping pairs decoder. Conforming volumes are unaffected.
How severe is CVE-2026-89614?
CVE-2026-89614 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2026-89614?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST