{"cve":"CVE-2026-89621","nvd":{"published":"2026-09-11T20:19:47.397","modified":"2026-10-19T09:17:58.880","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: mcp2221: validate report size in mcp2221_raw_event()\n\nmcp2221_raw_event() never validates the size of incoming HID reports.\nIn the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3]\nas the copy length without checking that 4 + data[3] bytes actually\nexist in the received report. A malicious or misbehaving USB device can\nsend a short report with a large data[3], causing the memcpy to read\npast the valid report data in the HID transfer buffer and leak\nuninitialized kernel memory back to userspace through the I2C/SMBus\nread path.\n\nAdd a minimum size check at entry and validate that the source range\nfits within the received report before the copy.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/127de5919820f88a9d55e8371ad4ac49f625f4c5","https://git.kernel.org/stable/c/2c9a6998c19503626c57a2267bf279e204113079","https://git.kernel.org/stable/c/7c18fb36708a97ff6772825cc087b6d537bbf0d5","https://git.kernel.org/stable/c/b2c67dc0e30c308647bbd9b9e5d69a44c9d2733d","https://git.kernel.org/stable/c/bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-89621","score":0.0022,"percentile":0.12414,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}