CVE-2026-72209ntfs: validate attribute values on lookup
- 9.8CriticalCVSS base score
- 0.55%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: ntfs: validate attribute values on lookup ntfs_attr_find() and ntfs_external_attr_find() check that generic resident attribute values fit in their attribute records and that fixed-size resident values are large enough. For variable-length resident formats, however, the fixed part is not enough: embedded length fields can still point callers past the resident value. A crafted image can set a small resident $FILE_NAME value_length while leaving file_name_length large. Callers then trust file_name_length and read past the resident value when converting or comparing the name. This was reproduced with a crafted image under KASAN as a slab-out-of-bounds read from the kmalloc-1k MFT record copy. The stack included ntfs_lookup(), ntfs_iget(), ntfs_read_locked_inode(), ntfs_attr_name_get(), ntfs_ucstonls(), and utf16s_to_utf8s(). Add a shared attribute value validator and use it before a lookup path can return an attribute, including the AT_UNUSED enumeration case where callers inspect returned attributes directly. The helper validates resident value bounds, minimum resident value sizes, variable-length $FILE_NAME fields, and non-resident mapping-pairs metadata that was previously checked separately in both lookup paths. This also preserves the intended resident @val matching semantics in the external attribute lookup path. The old duplicated validation block overwrote the actual resident value length with the type-specific minimum length before comparing @val, so variable-length resident values could fail to match even when the bytes were identical. Keep the comparison on the actual value length, and make ntfs_attrlist_entry_add() compare resident attributes with lowest_vcn zero instead of reading the non-resident union member after a successful resident match. Reject non-resident $FILE_NAME records too: the format requires $FILE_NAME to be resident and callers treat returned records as resident.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 2 days later
· 2 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.55% · top 53% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-58967 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-72209)Record last updated .