{"cve":"CVE-2021-47255","nvd":{"published":"2024-05-21T15:15:14.303","modified":"2026-06-17T04:17:01.567","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nkvm: LAPIC: Restore guard to prevent illegal APIC register access\n\nPer the SDM, \"any access that touches bytes 4 through 15 of an APIC\nregister may cause undefined behavior and must not be executed.\"\nWorse, such an access in kvm_lapic_reg_read can result in a leak of\nkernel stack contents. Prior to commit 01402cf81051 (\"kvm: LAPIC:\nwrite down valid APIC registers\"), such an access was explicitly\ndisallowed. Restore the guard that was removed in that commit.","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:H","score":7.1},"cwes":[],"references":["https://git.kernel.org/stable/c/018685461a5b9a9a70e664ac77aef0d7415a3fd5","https://git.kernel.org/stable/c/218bf772bddd221489c38dde6ef8e917131161f6","https://git.kernel.org/stable/c/a2aff09807fbe4018c269d3773a629949058b210","https://git.kernel.org/stable/c/bf99ea52970caeb4583bdba1192c1f9b53b12c84","https://git.kernel.org/stable/c/018685461a5b9a9a70e664ac77aef0d7415a3fd5"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47255","score":0.00244,"percentile":0.15656,"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."]}