Vulnerability-Lookup

CVE-2026-64267 (GCVE-0-2026-64267)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-25 08:49

Title

fuse: avoid 32-bit prune notification count wrap

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/6e2d84fdeac05bfd8…
https://git.kernel.org/stable/c/c78c4b242299bc581…
https://git.kernel.org/stable/c/54243797cedf55447…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3f29d59e92a96d843c2ff10ebfed92ac26878658 , < 6e2d84fdeac05bfd858e84a76353fdb84f23a43e (git) Affected: 3f29d59e92a96d843c2ff10ebfed92ac26878658 , < c78c4b242299bc581e4987e5c2786c6f4760c516 (git) Affected: 3f29d59e92a96d843c2ff10ebfed92ac26878658 , < 54243797cedf55447b4c5d560e8cd709900061ae (git)
Linux	Linux	Affected: 6.18 Unaffected: 0 , < 6.18 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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{
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      "affected": [
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          "programFiles": [
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              "versionType": "git"
            },
            {
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              "versionType": "git"
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              "lessThan": "54243797cedf55447b4c5d560e8cd709900061ae",
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          "versions": [
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              "version": "7.1.4",
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                  "vulnerable": true
                }
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              "negate": false,
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            }
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        }
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: avoid 32-bit prune notification count wrap\n\nFUSE_NOTIFY_PRUNE validates the nodeid payload length with:\n\n    size - sizeof(outarg) != outarg.count * sizeof(u64)\n\nOn 32-bit kernels, size_t is also 32 bits, so the daemon-controlled\ncount multiplication can wrap.  A prune notification with count\n0x20000000 and no nodeid payload passes the check, enters the copy\nloop, and asks the device copy path to read nodeids that are not\npresent in the userspace write buffer.  In QEMU this reaches the\nfuse_copy_fill() BUG_ON(!err) path.\n\nValidate the payload length with array_size() instead.  That accepts\nexactly the same valid messages, but avoids wrapping arithmetic before\nthe copy loop consumes the count."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:49:15.720Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
        {
          "url": "https://git.kernel.org/stable/c/54243797cedf55447b4c5d560e8cd709900061ae"
        }
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      "title": "fuse: avoid 32-bit prune notification count wrap",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
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    "datePublished": "2026-07-25T08:49:15.720Z",
    "dateReserved": "2026-07-19T15:36:31.775Z",
    "dateUpdated": "2026-07-25T08:49:15.720Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:46:58Z",
      "cve": "CVE-2026-64267",
      "id": "CVE-2026-64267",
      "initial_release_date": "2026-07-25T16:46:58Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64267",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64267.json",
      "version": "2"
    }
  }
}

GHSA-PJ3G-7699-4M62

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

fuse: avoid 32-bit prune notification count wrap

FUSE_NOTIFY_PRUNE validates the nodeid payload length with:

size - sizeof(outarg) != outarg.count * sizeof(u64)

On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path.

Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64267"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:06Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: avoid 32-bit prune notification count wrap\n\nFUSE_NOTIFY_PRUNE validates the nodeid payload length with:\n\n    size - sizeof(outarg) != outarg.count * sizeof(u64)\n\nOn 32-bit kernels, size_t is also 32 bits, so the daemon-controlled\ncount multiplication can wrap.  A prune notification with count\n0x20000000 and no nodeid payload passes the check, enters the copy\nloop, and asks the device copy path to read nodeids that are not\npresent in the userspace write buffer.  In QEMU this reaches the\nfuse_copy_fill() BUG_ON(!err) path.\n\nValidate the payload length with array_size() instead.  That accepts\nexactly the same valid messages, but avoids wrapping arithmetic before\nthe copy loop consumes the count.",
  "id": "GHSA-pj3g-7699-4m62",
  "modified": "2026-07-25T12:31:28Z",
  "published": "2026-07-25T12:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64267"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/54243797cedf55447b4c5d560e8cd709900061ae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6e2d84fdeac05bfd858e84a76353fdb84f23a43e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c78c4b242299bc581e4987e5c2786c6f4760c516"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64267 (GCVE-0-2026-64267)

GHSA-PJ3G-7699-4M62

Tags

Sightings

Nomenclature