{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.96-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.4-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux-6.12"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.100-1~deb12u1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  ALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()  snd_seq_event_dup() copies an incoming event into a pool cell and, in the UMP-enabled build, clears the trailing cell-\u003eump.raw.extra word that the memcpy() did not cover.  The guard deciding whether to clear it compares the copied size against sizeof(cell-\u003eevent):  \tmemcpy(\u0026cell-\u003eump, event, size); \tif (size \u003c sizeof(cell-\u003eevent)) \t\tcell-\u003eump.raw.extra = 0;  For a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) == sizeof(cell-\u003eevent), so the condition is false and the extra word keeps stale data.  The cell pool is allocated with kvmalloc() (not zeroed) and cells are reused via a free list, so that word holds uninitialised heap or leftover event data.  When such a cell is delivered to a UMP client (client-\u003emidi_version \u003e 0) that set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it unconverted -- snd_seq_read() reads it out as the larger struct snd_seq_ump_event and copies the stale word to user space, a 4-byte kernel heap infoleak to an unprivileged /dev/snd/seq client.  Compare against sizeof(cell-\u003eump) instead, so the trailing word is zeroed for every event shorter than the UMP cell.",
  "id": "DEBIAN-CVE-2026-64479",
  "modified": "2026-09-14T16:47:34.605552513Z",
  "published": "2026-07-25T10:17:33.493Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-64479"
    }
  ],
  "upstream": [
    "CVE-2026-64479"
  ]
}