{"cve":"CVE-2025-39793","nvd":{"published":"2025-09-12T16:15:33.590","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/memmap: cast nr_pages to size_t before shifting\n\nIf the allocated size exceeds UINT_MAX, then it's necessary to cast\nthe mr->nr_pages value to size_t to prevent it from overflowing. In\npractice this isn't much of a concern as the required memory size will\nhave been validated upfront, and accounted to the user. And > 4GB sizes\nwill be necessary to make the lack of a cast a problem, which greatly\nexceeds normal user locked_vm settings that are generally in the kb to\nmb range. However, if root is used, then accounting isn't done, and\nthen it's possible to hit this issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/33503c083fda048c77903460ac0429e1e2c0e341","https://git.kernel.org/stable/c/a69a9b53c54e2d33e2a5b1ea4a9a71fd01c6cf3a","https://git.kernel.org/stable/c/c6a2706e08b8a1b2d3740161c0977d38e596c1ee"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39793","score":0.00154,"percentile":0.04512,"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."]}