CVE-2026-89611
Received
Received - Intake
NTFS Attribute Offset Validation Flaw
Vulnerability report for CVE-2026-89611, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-11
Last updated on: 2026-09-11
Assigner: kernel.org
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
