Vulnerability-Lookup

GHSA-49P8-H7PF-GRWP

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-27 06:30

Details

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

fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues

fuse_uring_async_stop_queues() might run when the last reference on ring->queue_refs was already dropped.

In order to avoid an early destruction a reference on struct fuse_conn is now taken before starting fuse_uring_async_stop_queues() and that reference is only released when that delayed work queue terminates.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64261"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:06Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues\n\nfuse_uring_async_stop_queues() might run when the last reference\non ring-\u003equeue_refs was already dropped.\n\nIn order to avoid an early destruction a reference on struct fuse_conn\nis now taken before starting fuse_uring_async_stop_queues() and that\nreference is only released when that delayed work queue terminates.",
  "id": "GHSA-49p8-h7pf-grwp",
  "modified": "2026-07-27T06:30:31Z",
  "published": "2026-07-25T12:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64261"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/23a356e0bd96c8d5fb3ddff069f692bf10cab5c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/95d7f50aff2a5f71557263ff25b97b2951f32bf8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d351da75066955144515cb2f9aa959f24a04287a"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64261 (GCVE-0-2026-64261)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:52

Title

fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues fuse_uring_async_stop_queues() might run when the last reference on ring->queue_refs was already dropped. In order to avoid an early destruction a reference on struct fuse_conn is now taken before starting fuse_uring_async_stop_queues() and that reference is only released when that delayed work queue terminates.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/23a356e0bd96c8d5f…
https://git.kernel.org/stable/c/95d7f50aff2a5f715…
https://git.kernel.org/stable/c/d351da75066955144…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1 (git) Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < 95d7f50aff2a5f71557263ff25b97b2951f32bf8 (git) Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < d351da75066955144515cb2f9aa959f24a04287a (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 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "23a356e0bd96c8d5fb3ddff069f692bf10cab5c1",
              "status": "affected",
              "version": "4a9bfb9b6850fec0685447aed280533cf980de70",
              "versionType": "git"
            },
            {
              "lessThan": "95d7f50aff2a5f71557263ff25b97b2951f32bf8",
              "status": "affected",
              "version": "4a9bfb9b6850fec0685447aed280533cf980de70",
              "versionType": "git"
            },
            {
              "lessThan": "d351da75066955144515cb2f9aa959f24a04287a",
              "status": "affected",
              "version": "4a9bfb9b6850fec0685447aed280533cf980de70",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/dev_uring.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues\n\nfuse_uring_async_stop_queues() might run when the last reference\non ring-\u003equeue_refs was already dropped.\n\nIn order to avoid an early destruction a reference on struct fuse_conn\nis now taken before starting fuse_uring_async_stop_queues() and that\nreference is only released when that delayed work queue terminates."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerability is reached locally through IORING_OP_URING_CMD on a FUSE or CUSE device and connection teardown; no network path invokes it.\nAC:L - The attacker controls ring-entry creation or cancellation and closing the final channel, allowing both sides of the race to be driven and retried.\nPR:L - The vulnerable io_uring handler has no capability check, and a basic user can access a delegated FUSE/CUSE device; FUSE also supports unprivileged user-namespace mounts.\nUI:N - The attacker can create the connection, issue concurrent io_uring operations, and initiate teardown without any separate victim action.\nS:U - Exploitation compromises the same host kernel security authority; this is standard local kernel privilege escalation rather than a VM or IOMMU boundary escape.\nC:H - The stale delayed worker accesses reclaimed kmalloc-192 ring, queue, and list objects, allowing heap replacement to turn the UAF into kernel-memory disclosure primitives.\nI:H - The worker performs list and synchronization operations through freed, reclaimable pointers, making arbitrary writes or control-flow hijacking and kernel code execution defensible.\nA:H - The bug has produced a KASAN slab-use-after-free in asynchronous queue teardown and can cause a kernel oops, panic, or unrecoverable list corruption."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:52:14.647Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/23a356e0bd96c8d5fb3ddff069f692bf10cab5c1"
        },
        {
          "url": "https://git.kernel.org/stable/c/95d7f50aff2a5f71557263ff25b97b2951f32bf8"
        },
        {
          "url": "https://git.kernel.org/stable/c/d351da75066955144515cb2f9aa959f24a04287a"
        }
      ],
      "title": "fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64261",
    "datePublished": "2026-07-25T08:49:11.999Z",
    "dateReserved": "2026-07-19T15:36:31.774Z",
    "dateUpdated": "2026-08-17T04:52:14.647Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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