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

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:52
VLAI
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.
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1 (git)
Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < 95d7f50aff2a5f71557263ff25b97b2951f32bf8 (git)
Affected: 4a9bfb9b6850fec0685447aed280533cf980de70 , < d351da75066955144515cb2f9aa959f24a04287a (git)
guessed Create a notification for this product.
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)
guessed Create a notification for this product.
Show details on NVD website

{
  "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": [
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            },
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              "version": "7.1.4",
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        }
      ],
      "metrics": [
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            "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"
      },
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          "url": "https://git.kernel.org/stable/c/23a356e0bd96c8d5fb3ddff069f692bf10cab5c1"
        },
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          "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",
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        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
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    "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",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-09-16",
      "epss": "0.00157",
      "percentile": "0.05267"
    },
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    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-07-27T06:08:53+00:00",
      "cve": "CVE-2026-64261",
      "id": "CVE-2026-64261",
      "initial_release_date": "2026-07-25T00:00:00+00:00",
      "product_status:known_not_affected": "275",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64261.json",
      "version": "3"
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    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-17T16:40:30Z",
      "cve": "CVE-2026-64261",
      "id": "CVE-2026-64261",
      "initial_release_date": "2026-07-25T16:47:06Z",
      "product_status:known_not_affected": "298",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64261",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64261.json",
      "version": "5"
    }
  }
}



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