{"cve":"CVE-2026-81009","nvd":{"published":"2026-09-11T20:19:09.687","modified":"2026-10-19T09:17:34.310","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/query: cap user size passed to copy_struct_to_user\n\nio_handle_query_entry() clamps hdr.size for the inbound copy_from_user()\nbut keeps the original user value as usize. copy_struct_to_user() uses\nthat usize and, when it is larger than the kernel result, clear_user()s\nthe trailing bytes.\n\nAs hdr.size is a __u32, a query can request nearly 4 GiB of zeroing,\nincluding on the error path where res_size stays 0. The interface is\nreachable without a ring via IORING_REGISTER_QUERY.\n\nReject sizes larger than PAGE_SIZE, as recommended for copy_struct_*\ninterfaces.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/2b8ad4981ecedb14c1fdd811ab977010b23933e6","https://git.kernel.org/stable/c/417e02f7b6051765b91cf1289071882eebd172e0","https://git.kernel.org/stable/c/ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-81009","score":0.00166,"percentile":0.05796,"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."]}