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CVE-2026-72210 (GCVE-0-2026-72210)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:54 – Updated: 2026-08-19 10:49
VLAI
Title
ntfs: fix off-by-one in mapping pairs decoding bounds checks
Summary
In the Linux kernel, the following vulnerability has been resolved: ntfs: fix off-by-one in mapping pairs decoding bounds checks In ntfs_mapping_pairs_decompress(), attr_end points one byte past the end of the attribute record: attr_end = (u8 *)attr + le32_to_cpu(attr->length); The two bounds checks validating that mapping pair data bytes fit within the attribute use strict greater-than (>), which allows a one-byte out-of-bounds read when the data extends exactly to attr_end: b = *buf & 0xf; if (b) { if (unlikely(buf + b > attr_end)) // off-by-one goto io_error; for (deltaxcn = (s8)buf[b--]; b; b--) deltaxcn = (deltaxcn << 8) + buf[b]; } When buf + b == attr_end, the check evaluates to false and buf[b] reads one byte past the valid attribute boundary. The same pattern appears in the LCN delta bytes check. Fix both checks to use >= so that buf[b] at exactly attr_end is correctly rejected as out of bounds.
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: 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 , < bfe835e535fe0aa5767fdd8116f62e835ba50b55 (git)
Affected: 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 , < 18760a74ef7c28df93726445b5595162e62ed341 (git)
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Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs/runlist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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              "status": "affected",
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          "vendor": "Linux",
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: fix off-by-one in mapping pairs decoding bounds checks\n\nIn ntfs_mapping_pairs_decompress(), attr_end points one byte past the\nend of the attribute record:\n\n    attr_end = (u8 *)attr + le32_to_cpu(attr-\u003elength);\n\nThe two bounds checks validating that mapping pair data bytes fit within\nthe attribute use strict greater-than (\u003e), which allows a one-byte\nout-of-bounds read when the data extends exactly to attr_end:\n\n  b = *buf \u0026 0xf;\n  if (b) {\n      if (unlikely(buf + b \u003e attr_end))   // off-by-one\n          goto io_error;\n      for (deltaxcn = (s8)buf[b--]; b; b--)\n          deltaxcn = (deltaxcn \u003c\u003c 8) + buf[b];\n  }\n\nWhen buf + b == attr_end, the check evaluates to false and buf[b] reads\none byte past the valid attribute boundary. The same pattern appears in\nthe LCN delta bytes check.\n\nFix both checks to use \u003e= so that buf[b] at exactly attr_end is\ncorrectly rejected as out of bounds."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The legacy NTFS driver is exported via nfsd and commonly shared over ksmbd; remote NFS/SMB reads on an NTFS-backed export reach ntfs_mapping_pairs_decompress() through VFS read/iomap and ntfs_map_runlist() without further local access.\nAC:L - An attacker fully controls a crafted NTFS image offline and can place mapping pairs to hit the exact off-by-one boundary, reliably triggering the flaw on mount or on the next access that decompresses that attribute extent.\nPR:N - Exploitation needs only the ability to trigger server-side parsing of the mounted volume (e.g., guest/anonymous SMB or permissive NFS export); no init-namespace root or CAP_SYS_ADMIN on the victim is required at trigger time.\nUI:N - After an administrator mounts the poisoned volume, a remote client can trigger the bug with protocol read/open operations alone; no additional end-user clicks, plug-in events, or mount actions are needed during exploitation.\nS:U - Impact stays within kernel/host context (metadata parsing, runlist corruption, and resulting I/O); it does not cross a VM, container, or IOMMU security boundary to another authority.\nC:H - The flawed bounds check permits a one-byte out-of-bounds kernel read past the attribute end, often into MFT record slack that may contain stale cached data, matching OOB-read disclosure impact.\nI:H - The leaked byte is folded into runlist length/LCN deltas, yielding attacker-influenced cluster mappings that can misdirect subsequent kernel block I/O and corrupt arbitrary on-volume metadata or file data.\nA:H - Corrupt runlists and failed decompression paths surface as ntfs_error/EIO during mount or I/O and can panic or wedge the node under repeated remote access, giving a practical denial-of-service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T10:49:39.287Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bfe835e535fe0aa5767fdd8116f62e835ba50b55"
        },
        {
          "url": "https://git.kernel.org/stable/c/18760a74ef7c28df93726445b5595162e62ed341"
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      "title": "ntfs: fix off-by-one in mapping pairs decoding bounds checks",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72210",
    "datePublished": "2026-08-15T05:54:05.527Z",
    "dateReserved": "2026-08-09T03:40:39.912Z",
    "dateUpdated": "2026-08-19T10:49:39.287Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72210",
      "date": "2026-09-16",
      "epss": "0.00516",
      "percentile": "0.42683"
    },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-18T16:29:03+00:00",
      "cve": "CVE-2026-72210",
      "id": "CVE-2026-72210",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ntfs: fix off-by-one in mapping pairs decoding bounds checks",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72210.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-10T02:08:21Z",
      "cve": "CVE-2026-72210",
      "id": "CVE-2026-72210",
      "initial_release_date": "2026-08-21T00:42:27Z",
      "product_status:known_affected": "333",
      "product_status:known_not_affected": "29",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-72210",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-72210.json",
      "version": "3"
    }
  }
}



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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.

Sightings

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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.
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  • 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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