Vulnerability-Lookup

CVE-2026-64259 (GCVE-0-2026-64259)

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

Title

fuse-uring: make a fuse_req on SQE commit only findable after memcpy

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: make a fuse_req on SQE commit only findable after memcpy Bad userspace might try to trick us and send commit SQEs request unique / commit-id of requests that are not even send to fuse-server (io_uring_cmd_done() not called) yet. fuse_uring_commit_fetch() ends the fuse request when the ring entry has a wrong state, but that could have caused a use-after-free with the memcpy operations in fuse_uring_send_in_task(). In order to avoid such races the call of fuse_uring_add_to_pq() is moved after the copy operations and just before completing the io-uring request - malicious userspace cannot find the request anymore until all prepration work in fuse-client/kernel is completed. This also moves fuse_uring_add_to_pq() a bit up in the code to avoid a forward declaration. Also not with a preparation commit, to make it easier to back port to older kernels.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/e1711479e9068ea31…
https://git.kernel.org/stable/c/a635f427d57e20121…
https://git.kernel.org/stable/c/1efd3d474fc0ba74d…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < e1711479e9068ea31b31353a702a51e639c3d059 (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < a635f427d57e2012102ae4886b48d8955c59fb86 (git) Affected: c090c8abae4b6b77a1bee116aa6c385456ebef96 , < 1efd3d474fc0ba74dfd984249bca78807d739812 (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (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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        {
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          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c"
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              "versionType": "git"
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            {
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        }
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      "cpeApplicability": [
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              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: make a fuse_req on SQE commit only findable after memcpy\n\nBad userspace might try to trick us and send commit SQEs request\nunique / commit-id of requests that are not even send to\nfuse-server (io_uring_cmd_done() not called) yet.\n\nfuse_uring_commit_fetch() ends the fuse request when the ring entry\nhas a wrong state, but that could have caused a use-after-free\nwith the memcpy operations in fuse_uring_send_in_task().\nIn order to avoid such races the call of fuse_uring_add_to_pq()\nis moved after the copy operations and just before completing\nthe io-uring request - malicious userspace cannot find the request\nanymore until all prepration work in fuse-client/kernel is completed.\n\nThis also moves fuse_uring_add_to_pq() a bit up in the code to\navoid a forward declaration. Also not with a preparation commit,\nto make it easier to back port to older kernels."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:49:10.756Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/a635f427d57e2012102ae4886b48d8955c59fb86"
        },
        {
          "url": "https://git.kernel.org/stable/c/1efd3d474fc0ba74dfd984249bca78807d739812"
        }
      ],
      "title": "fuse-uring: make a fuse_req on SQE commit only findable after memcpy",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64259",
    "datePublished": "2026-07-25T08:49:10.756Z",
    "dateReserved": "2026-07-19T15:36:31.773Z",
    "dateUpdated": "2026-07-25T08:49:10.756Z",
    "state": "PUBLISHED"
  },
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      "date": "2026-07-26",
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      "percentile": "0.09859"
    },
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    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:47:08Z",
      "cve": "CVE-2026-64259",
      "id": "CVE-2026-64259",
      "initial_release_date": "2026-07-25T16:47:08Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64259",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64259.json",
      "version": "2"
    }
  }
}

GHSA-6VP8-RVJ5-GC8C

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-uring: make a fuse_req on SQE commit only findable after memcpy

Bad userspace might try to trick us and send commit SQEs request unique / commit-id of requests that are not even send to fuse-server (io_uring_cmd_done() not called) yet.

fuse_uring_commit_fetch() ends the fuse request when the ring entry has a wrong state, but that could have caused a use-after-free with the memcpy operations in fuse_uring_send_in_task(). In order to avoid such races the call of fuse_uring_add_to_pq() is moved after the copy operations and just before completing the io-uring request - malicious userspace cannot find the request anymore until all prepration work in fuse-client/kernel is completed.

This also moves fuse_uring_add_to_pq() a bit up in the code to avoid a forward declaration. Also not with a preparation commit, to make it easier to back port to older kernels.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64259"
  ],
  "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-uring: make a fuse_req on SQE commit only findable after memcpy\n\nBad userspace might try to trick us and send commit SQEs request\nunique / commit-id of requests that are not even send to\nfuse-server (io_uring_cmd_done() not called) yet.\n\nfuse_uring_commit_fetch() ends the fuse request when the ring entry\nhas a wrong state, but that could have caused a use-after-free\nwith the memcpy operations in fuse_uring_send_in_task().\nIn order to avoid such races the call of fuse_uring_add_to_pq()\nis moved after the copy operations and just before completing\nthe io-uring request - malicious userspace cannot find the request\nanymore until all prepration work in fuse-client/kernel is completed.\n\nThis also moves fuse_uring_add_to_pq() a bit up in the code to\navoid a forward declaration. Also not with a preparation commit,\nto make it easier to back port to older kernels.",
  "id": "GHSA-6vp8-rvj5-gc8c",
  "modified": "2026-07-25T12:31:27Z",
  "published": "2026-07-25T12:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64259"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1efd3d474fc0ba74dfd984249bca78807d739812"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a635f427d57e2012102ae4886b48d8955c59fb86"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e1711479e9068ea31b31353a702a51e639c3d059"
    }
  ],
  "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-2026-64259 (GCVE-0-2026-64259)

GHSA-6VP8-RVJ5-GC8C

Tags

Sightings

Nomenclature