{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "369cd2121be440543280b91056de187f625d0dbb"
            },
            {
              "fixed": "a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f"
            },
            {
              "fixed": "d4026417e8184d13850a0bad4d96ceb6ed9f7152"
            },
            {
              "fixed": "29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0"
            },
            {
              "fixed": "5f4dbdb0a87596214076b20b94f2b71b522170b3"
            },
            {
              "fixed": "a6e9a4939e359599701b1da351e84f72e021443a"
            },
            {
              "fixed": "60d696a037eeeedfb57756dfe7ec08a1587c8631"
            },
            {
              "fixed": "710183888174639a15fcec16cd1af766b8480bb7"
            },
            {
              "fixed": "8e80af52db652fbc41320eee45a4f73bc029faf2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.11.0"
            },
            {
              "fixed": "5.10.261"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64514.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry.",
  "id": "CVE-2026-64514",
  "modified": "2026-07-27T03:56:43.860997288Z",
  "published": "2026-07-25T08:52:05.878Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64514.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64514"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "userfaultfd: gate must_wait writability check on pte_present()"
}