{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "6389f2c135311c4ce7c08c3b29145c8f95aacf1f"
            },
            {
              "fixed": "d7649aa11089a93ea2285c210397aa67e5800766"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "d7e2ce72833bb23a82b4201fbed7214cc04a4a8c"
            },
            {
              "fixed": "a224c84e5d3d35708c082c84ad12d81d90762195"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "46397622a3fa8372b8fda0f04b33d16923b03b1b"
            },
            {
              "fixed": "ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a"
            },
            {
              "fixed": "fb1aa5082847b98f44f9c6272aee9d0dca9244f0"
            },
            {
              "fixed": "651ba82fe2a144bc7356d940bfd235c3810b0549"
            },
            {
              "fixed": "6ded42615fa1f4949925afd0a8a9e1ab3bf96202"
            },
            {
              "fixed": "435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.5.0"
            },
            {
              "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-2026-64479.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()\n\nsnd_seq_event_dup() copies an incoming event into a pool cell and, in\nthe UMP-enabled build, clears the trailing cell-\u003eump.raw.extra word that\nthe memcpy() did not cover.  The guard deciding whether to clear it\ncompares the copied size against sizeof(cell-\u003eevent):\n\n\tmemcpy(\u0026cell-\u003eump, event, size);\n\tif (size \u003c sizeof(cell-\u003eevent))\n\t\tcell-\u003eump.raw.extra = 0;\n\nFor a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) ==\nsizeof(cell-\u003eevent), so the condition is false and the extra word keeps\nstale data.  The cell pool is allocated with kvmalloc() (not zeroed) and\ncells are reused via a free list, so that word holds uninitialised heap\nor leftover event data.\n\nWhen such a cell is delivered to a UMP client (client-\u003emidi_version \u003e 0)\nthat set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it\nunconverted -- snd_seq_read() reads it out as the larger struct\nsnd_seq_ump_event and copies the stale word to user space, a 4-byte\nkernel heap infoleak to an unprivileged /dev/snd/seq client.\n\nCompare against sizeof(cell-\u003eump) instead, so the trailing word is zeroed\nfor every event shorter than the UMP cell.",
  "id": "CVE-2026-64479",
  "modified": "2026-07-27T03:56:11.497593677Z",
  "published": "2026-07-25T08:51:41.006Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/651ba82fe2a144bc7356d940bfd235c3810b0549"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6ded42615fa1f4949925afd0a8a9e1ab3bf96202"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a224c84e5d3d35708c082c84ad12d81d90762195"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d7649aa11089a93ea2285c210397aa67e5800766"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fb1aa5082847b98f44f9c6272aee9d0dca9244f0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64479.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64479"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "ALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()"
}