{"id":"CVE-2021-26910","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-26910","generatedAt":"2026-10-27T22:33:54.582Z","title":"Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.","description":"Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.","published":"2021-02-08T20:15:13.000Z","lastModified":"2026-06-17T03:43:59.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":7,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-367"],"affected":["firejail project/firejail","debian/debian linux"],"epss":{"score":0.00444,"percentile":0.38402,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2021/02/09/1","tags":["Exploit","Mailing List","Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/netblue30/firejail/releases/tag/0.9.64.4","tags":["Release Notes","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202105-19","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.debian.org/security/2021/dsa-4849","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2021/02/09/1","tags":["Exploit","Mailing List","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/netblue30/firejail/releases/tag/0.9.64.4","tags":["Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202105-19","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2021/dsa-4849","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-26910","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}