{"cve":"CVE-2021-20263","nvd":{"published":"2021-03-09T18:15:15.593","modified":"2026-06-17T03:33:33.983","status":"Modified","description":"A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","score":3.3},"cwes":["CWE-281"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=1933668","https://security.gentoo.org/glsa/202208-27","https://security.netapp.com/advisory/ntap-20210507-0002/","https://www.openwall.com/lists/oss-security/2021/03/08/1","https://bugzilla.redhat.com/show_bug.cgi?id=1933668"],"products":["qemu:qemu"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-20263","score":0.00377,"percentile":0.31664,"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."]}