{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "a82dfd33d1237f6c0fb8a7077022189d1fc7ec98"
            },
            {
              "fixed": "2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb"
            },
            {
              "fixed": "53fed4061a09755de99c89fdc7fae5b794da455f"
            },
            {
              "fixed": "200d58c851b8f63f77a05570072dd20f79bc3681"
            },
            {
              "fixed": "8206d173d18ef5a077423119f4e9a93cb3a6f4eb"
            },
            {
              "fixed": "6b964941bbfe6e0f18b1a5e008486dbb62df440a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.144"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.95"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.38"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63821.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtw88: usb: fix memory leaks on USB write failures\n\nWhen rtw_usb_write_port() fails to submit a USB Request Block (URB)\n(e.g., due to device disconnect or ENOMEM), the completion callback is\nnever executed.\n\nCurrently, the driver ignores the return value of rtw_usb_write_port()\nin rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these\nfunctions rely on the completion callback to free the socket buffers\n(skbs) and the transaction control block (txcb), a submission failure\nresults in:\n1. A memory leak of the allocated skb in rtw_usb_write_data().\n2. A memory leak of the txcb structure and all aggregated skbs in\n   rtw_usb_tx_agg_skb().\n\nFix this by checking the return value of rtw_usb_write_port(). If it\nfails, explicitly free the skb in rtw_usb_write_data(), and properly\npurge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb().\n\nThe issue was discovered in practice during device disconnect/reconnect\nscenarios and memory pressure conditions. Tested by verifying normal TX\noperation continues after the fix without regressions.",
  "id": "CVE-2026-63821",
  "modified": "2026-07-21T03:41:59.849008407Z",
  "published": "2026-07-19T12:02:18.751Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63821.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63821"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "wifi: rtw88: usb: fix memory leaks on USB write failures"
}