{"cve":"CVE-2021-22543","nvd":{"published":"2021-05-26T11:15:08.623","modified":"2026-06-17T03:37:24.440","status":"Modified","description":"An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L","score":8.7},"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":["CWE-119"],"references":["http://www.openwall.com/lists/oss-security/2021/06/26/1","https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584","https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html","https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4G5YBUVEPHZYXMKNGBZ3S6INFCTEEL4E/"],"products":["debian:debian_linux","fedoraproject:fedora","linux:linux_kernel","netapp:cloud_backup","netapp:h300e_firmware","netapp:h300s_firmware","netapp:h410c_firmware","netapp:h410s_firmware","netapp:h500e_firmware","netapp:h500s_firmware","netapp:h700e_firmware","netapp:h700s_firmware","netapp:solidfire_baseboard_management_controller_firmware"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-22543","score":0.0066,"percentile":0.51606,"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."]}