CVE-2026-89611: ntfs: validate non-resident attribute offsets

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-11 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: ntfs: validate non-resident attribute offsets ntfs_attr_update_meta() shifts the attribute name when converting between non-sparse and sparse attributes. Converting to sparse also adds the compressed_size field before the name and mapping pairs, requiring eight additional bytes in the attribute record. However, the validator does not check that name_offset is within safe boundaries for these operations or that the additional space is available. A malicious MFT record could set name_offset such that: 1. The name is positioned at the very end of a non-sparse attribute. Converting to sparse would shift the name forward by 8 bytes, writing beyond the attribute boundary. 2. The name overlaps with the mapping pairs, causing corruption during conversion. Add validation to ensure: - For named attributes, name_offset is within valid bounds - Name does not extend beyond the attribute or overlap with mapping pairs - For non-sparse, non-compressed attributes, eight bytes are available after mapping_pairs_offset for the compressed_size field The space check also covers unnamed attributes, for which name_offset = 0 is valid and no name range needs to be checked.

Affected products

Linux kernel: before 7.2.4 — fixed in 7.2.4, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.2.4, 7.3. Check the vendor advisory for mitigations.

References

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