{"cve":"CVE-2021-3735","nvd":{"published":"2022-08-26T16:15:09.467","modified":"2026-06-17T04:05:39.797","status":"Modified","description":"A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while handling a host-to-device Register FIS (Frame Information Structure) packet from the guest. A privileged user inside the guest could use this flaw to hang the QEMU process on the host, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","score":4.4},"cwes":["CWE-400","CWE-667"],"references":["https://access.redhat.com/security/cve/CVE-2021-3735","https://bugzilla.redhat.com/show_bug.cgi?id=1997184","https://security-tracker.debian.org/tracker/CVE-2021-3735","https://access.redhat.com/security/cve/CVE-2021-3735","https://bugzilla.redhat.com/show_bug.cgi?id=1997184"],"products":["debian:debian_linux","qemu:qemu"],"source":"nvd","synced_at":"2026-10-19T21:35:14.992143698+00:00"},"epss":{"cve":"CVE-2021-3735","score":0.00206,"percentile":0.10658,"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."]}