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CVE-2026-89611 (GCVE-0-2026-89611)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:45 – Updated: 2026-09-13 06:31
VLAI
Title
ntfs: validate non-resident attribute offsets
Summary
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.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < cd7b3dc7557faadeea626034e3bac68a449851ef (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a83e82b0ec3ae523028e24813f23f18b43e8fc1c (git)
Affected: 0 , < 7.2.4 (semver)
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Linux Linux Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
            "fs/ntfs/attrib.c"
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        }
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            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
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              "lang": "en",
              "value": "AV:N - fs/ntfs registers ntfs_export_ops, so ksmbd/nfsd VFS write, truncate, create, and ksmbd vfs_fallocate(FALLOC_FL_PUNCH_HOLE) on an exported NTFS volume reach ntfs_attr_update_mapping_pairs() \u2192 ntfs_attr_update_meta() without local shell access.\nAC:L - A crafted MFT record with a malicious name_offset or too little mapping-pairs slack makes ntfs_attr_update_meta() memmove the name or add compressed_size on every attacker-driven punch-hole, sparse extend, or directory update; no race or uninfluenced layout is required.\nPR:N - Exploitation needs only write or create access on the mounted NTFS volume, including guest/anonymous SMB or world-writable NFS on a misconfigured export and automounted removable media; no init-namespace root or CAP_SYS_ADMIN is required.\nUI:N - Once the NTFS volume is rw-mounted and optionally exported (or automounted from shared/removable storage), the attacker triggers sparsity conversion via fallocate, truncate, write, or create; no further victim clicks or cooperative opens are needed.\nS:U - The overflow corrupts the kmalloc MFT-record buffer and adjacent host-kernel heap during filesystem metadata updates; this is standard kernel privilege impact, not a VM escape, IOMMU bypass, or sandbox scope change.\nC:H - memmove of the attacker-controlled attribute name and later mapping-pairs builds write past the kmalloc(mft_record_size) slab into neighboring objects, which per kernel CNA guidance yields an information-disclosure primitive from corrupted adjacent heap contents.\nI:H - Converting to or from sparse performs an out-of-bounds heap write of attacker-chosen name bytes and can shift mapping_pairs_offset so ntfs_mapping_pairs_build() stores runs past the record, enabling slab corruption and control-flow hijack.\nA:H - Overflowing the kmalloc MFT-record slab into adjacent memory can oops or panic the kernel, and even failed exploitation leaves inconsistent MFT metadata that crashes later lookups or writeback."
            }
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        "dateUpdated": "2026-09-13T06:31:48.805Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/cd7b3dc7557faadeea626034e3bac68a449851ef"
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          "url": "https://git.kernel.org/stable/c/a83e82b0ec3ae523028e24813f23f18b43e8fc1c"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89611",
    "datePublished": "2026-09-11T19:45:12.646Z",
    "dateReserved": "2026-09-11T19:38:34.734Z",
    "dateUpdated": "2026-09-13T06:31:48.805Z",
    "state": "PUBLISHED"
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-13T06:59:09+00:00",
      "cve": "CVE-2026-89611",
      "id": "CVE-2026-89611",
      "initial_release_date": "2026-09-11T19:45:12.646000+00:00",
      "product_status:known_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Linux kernel: NTFS driver memory corruption due to improper attribute offset validation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89611.json",
      "version": "3"
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.