{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.4.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "8469084dfae85f854555f0607f2c838dad097235"
            },
            {
              "fixed": "1b1ecdc438092cdd469319a0d51cba6cf82e06f4"
            }
          ],
          "repo": "https://github.com/zephyrproject-rtos/zephyr",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-68cj-3hg4-5vpm"
  ],
  "database_specific": {
    "cna_assigner": "zephyr",
    "cwe_ids": [
      "CWE-822",
      "CWE-862"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9771.json"
  },
  "details": "The flash_copy() system call is verified by z_vrfy_flash_copy() in drivers/flash/flash_util.c. On builds with CONFIG_USERSPACE enabled, this handler is the kernel-side trust boundary for a user-mode caller. Prior to the fix it validated only the output buffer (K_SYSCALL_MEMORY_WRITE) and passed the two struct device * arguments, src_dev and dst_dev, directly into the implementation without any object validation — unlike every sibling flash syscall, which guards its device pointer with K_SYSCALL_DRIVER_FLASH.\n\nA user-mode thread fully controls the values of src_dev/dst_dev and the contents of its own address space. The implementation z_impl_flash_copy() dereferences these pointers and calls through their driver-API function tables (e.g. api-\u003eget_parameters(dst_dev), flash_read(src_dev, ...), flash_write(dst_dev, ...)). By supplying a pointer to a forged struct device whose api table contains attacker-chosen function pointers, an unprivileged thread can cause the kernel to call arbitrary code in supervisor mode; passing any arbitrary or invalid address otherwise yields a kernel crash or out-of-bounds read.\n\nThe result is a local privilege escalation out of the userspace sandbox (with kernel denial-of-service and information disclosure as lesser outcomes). The fix adds K_SYSCALL_DRIVER_FLASH(src_dev, read) and K_SYSCALL_DRIVER_FLASH(dst_dev, write) to z_vrfy_flash_copy(), which verify each device is a registered flash-driver kernel object the calling thread is permitted to use before any dereference, closing the path completely.",
  "id": "CVE-2026-9771",
  "modified": "2026-08-28T11:30:31.820616209Z",
  "published": "2026-08-17T16:18:52.514Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9771.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-68cj-3hg4-5vpm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9771"
    },
    {
      "type": "FIX",
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/1b1ecdc438092cdd469319a0d51cba6cf82e06f4"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zephyrproject-rtos/zephyr"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Missing device-pointer validation in flash_copy() syscall allows userspace privilege escalation"
}