Search for vulnerabilities
Vulnerability details: VCID-d7wz-2aws-e7cw
Vulnerability ID VCID-d7wz-2aws-e7cw
Aliases CVE-2021-26910
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
System Score Found at
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-26910
cvssv2 6.9 https://nvd.nist.gov/vuln/detail/CVE-2021-26910
cvssv3.1 7.0 https://nvd.nist.gov/vuln/detail/CVE-2021-26910
archlinux High https://security.archlinux.org/AVG-1545
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-26910
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26910
https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b
https://github.com/netblue30/firejail/releases/tag/0.9.64.4
https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html
https://security.gentoo.org/glsa/202105-19
https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/
https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt
https://www.debian.org/security/2021/dsa-4849
http://www.openwall.com/lists/oss-security/2021/02/09/1
ASA-202102-26 https://security.archlinux.org/ASA-202102-26
AVG-1545 https://security.archlinux.org/AVG-1545
cpe:2.3:a:firejail_project:firejail:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:firejail_project:firejail:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
CVE-2021-26910 https://nvd.nist.gov/vuln/detail/CVE-2021-26910
USN-5141-1 https://usn.ubuntu.com/5141-1/
No exploits are available.
Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C Found at https://nvd.nist.gov/vuln/detail/CVE-2021-26910
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-26910
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.15569
EPSS Score 0.0005
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:40:52.513049+00:00 Ubuntu USN Importer Import https://usn.ubuntu.com/5141-1/ 37.0.0