{"cve":"CVE-2023-23586","nvd":{"published":"2023-02-17T13:15:10.737","modified":"2026-06-17T05:37:30.960","status":"Modified","description":"Due to a vulnerability in the io_uring subsystem, it is possible to leak kernel memory information to the user process. timens_install calls current_is_single_threaded to determine if the current process is single-threaded, but this call does not consider io_uring's io_worker threads, thus it is possible to insert a time namespace's vvar page to process's memory space via a page fault. When this time namespace is destroyed, the vvar page is also freed, but not removed from the process' memory, and a next page allocated by the kernel will be still available from the user-space process and can leak memory contents via this (read-only) use-after-free vulnerability. We recommend upgrading past version 5.10.161 or commit  788d0824269bef539fe31a785b1517882eafed93 https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring","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:N/A:N","score":5.5},"cwes":["CWE-416"],"references":["https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring?h=linux-5.10.y&id=788d0824269bef539fe31a785b1517882eafed93","https://kernel.dance/#788d0824269bef539fe31a785b1517882eafed93","https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring?h=linux-5.10.y&id=788d0824269bef539fe31a785b1517882eafed93","https://kernel.dance/#788d0824269bef539fe31a785b1517882eafed93"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:37:38.595364862+00:00"},"epss":{"cve":"CVE-2023-23586","score":0.00268,"percentile":0.18936,"date":"2026-10-31"},"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."]}