{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0636e65c825e810ad97f154606365870152d402f"
            }
          ],
          "repo": "https://github.com/zephyrproject-rtos/zephyr",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-4x98-6536-cwjv"
  ],
  "database_specific": {
    "cna_assigner": "zephyr",
    "cwe_ids": [
      "CWE-362"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19571.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "3.3.0"
          },
          {
            "fixed": "4.5.0"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "The ITE IT8xxx2 SHI host-command backend (subsys/mgmt/ec_host_cmd/backends/ec_host_cmd_backend_shi_ite.c) copied the 8-byte host-command request header from the SPI Rx FIFO directly into the shared receive buffer data-\u003ein_msg and only afterwards checked the protocol version and the derived packet length. The interrupt handler also accepted a chip-select assertion and an Rx-valid-length (RVLI) interrupt in any driver state other than SHI_STATE_DISABLED, so a new header could be parsed while the host-command thread was still processing the previous request out of the very same buffer.\n\nThe host processor is the SPI controller and drives both chip select and the clock. After sending a well-formed request it can immediately de-assert chip select — which returns the driver to the ready state and re-enables the FIFO — and start a second transaction carrying a header with data_len = 0xFFFF. Those eight bytes are written into in_msg before the oversized length is rejected, so they land in a buffer whose contents verify_rx() in subsys/mgmt/ec_host_cmd/ec_host_cmd_handler.c has already validated. If this lands in the window before the host-command thread executes args.input_buf_size = rx_header-\u003edata_len, the framework hands the registered command handler a 65535-byte input length over a 256-byte buffer.\n\nThe result is an out-of-bounds read of up to roughly 64 KiB beyond the request buffer: command handlers that copy or echo input_buf_size bytes disclose adjacent embedded-controller memory back to the host or overflow the response buffer, and a read past the end of SRAM faults the controller. The same race also allows cmd_id and cmd_ver to be swapped after checksum verification and after handler lookup. Exploitation requires the ability to drive the inter-processor SHI bus (a compromised host OS or physical access to the SPI lines) and winning a timing race, which the SPI controller can retry indefinitely.\n\nThe fix parses the header into a local struct ec_host_cmd_request_header and copies it into in_msg only after the length has been bounded by sizeof(data-\u003ein_msg), and ignores chip-select and RVLI interrupts outside SHI_STATE_READY_TO_RECV/SHI_STATE_RECEIVING. A residual, bounded race remains: an end-of-transaction interrupt still resets the state to ready while the host-command thread owns the buffer, so a valid second request can still overwrite the in-flight request's contents, unlike the NPCX backend which parks in SHI_STATE_CNL_RESP_NOT_RDY while the buffer is in use.",
  "id": "CVE-2026-19571",
  "modified": "2026-10-11T02:30:23.257559059Z",
  "published": "2026-10-09T07:16:40.717Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19571.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4x98-6536-cwjv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19571"
    },
    {
      "type": "FIX",
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/0636e65c825e810ad97f154606365870152d402f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zephyrproject-rtos/zephyr"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Race condition in ITE IT8xxx2 SHI host-command backend lets a second SPI request write an unvalidated length into the in-flight request buffer"
}