{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "14fe4f75fd5309d6b75f8e840ada88912b374207"
            },
            {
              "fixed": "f29243c211928114f8b906e0a3fee77c236f14c8"
            },
            {
              "fixed": "e0c3edd86414534cfd179fefe45b38c29c01ae7a"
            },
            {
              "fixed": "6b52211eba213c461f68922708a99d8190c1fcd5"
            },
            {
              "fixed": "74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b"
            },
            {
              "fixed": "c2ac9287e89916da684c2a548798351e63eb59ee"
            },
            {
              "fixed": "705dd6dcbc0ea87351c660c1a6443f85f1001c76"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "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": "6.12.97"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.40"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74339.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Clear variable event pointer on read\n\nsnd_seq_read() copies a queued variable-length event header to userspace\nbefore expanding the payload. Queued variable-length events use\nSNDRV_SEQ_EXT_CHAINED internally, and data.ext.ptr points at the first\nextension cell.\n\nThe read side strips SNDRV_SEQ_EXT_* bits from data.ext.len before the\ncopy, but it leaves data.ext.ptr untouched. A userspace sequencer client\ncan therefore write a direct variable event to itself and read back the\nextension-cell kernel address from the returned header.\n\nClear the temporary header pointer before copy_to_user(). The original\nqueued event remains unchanged and is still passed to\nsnd_seq_expand_var_event(), so payload expansion keeps using the\ninternal chain.",
  "id": "CVE-2026-74339",
  "modified": "2026-08-18T03:31:04.499605870Z",
  "published": "2026-08-15T05:58:29.888Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/14fe4f75fd5309d6b75f8e840ada88912b374207"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6b52211eba213c461f68922708a99d8190c1fcd5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/705dd6dcbc0ea87351c660c1a6443f85f1001c76"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c2ac9287e89916da684c2a548798351e63eb59ee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e0c3edd86414534cfd179fefe45b38c29c01ae7a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f29243c211928114f8b906e0a3fee77c236f14c8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74339.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74339"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ALSA: seq: Clear variable event pointer on read"
}