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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firejail | 0.9.64.4-1 | — |
| Debian 13 | firejail | 0.9.64.4-1 | — |
| Debian 12 | firejail | 0.9.64.4-1 | — |
| Debian 10 | firejail | 0.9.58.2-2+deb10u2 | DSA-4849-1 |
| Debian 9 | firejail | 0.9.44.8-2+deb9u2 | DLA-2554-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | firejail | 0.9.62-3ubuntu0.1 | USN-5141-1 |
| Ubuntu 18.04 LTS | firejail | No fix yet | — |
| Ubuntu 16.04 LTS | firejail | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | firejail | 0.9.64.4-lp152.3.6.1 | openSUSE-SU-2021:0271-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.13 | firejail | 0.9.64.4-r0 | — |
Advisories 4
- USN-5141-1 firejail vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-4849-1 firejail - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2554-1 firejail - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2021:0271-1 Security update for firejail SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b
- https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt
- https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/
- https://github.com/netblue30/firejail/releases/tag/0.9.64.4
- [oss-security] 20210209 Re: [cve-pending] Firejail: root privilege escalation in OverlayFS code mailing-list
- DSA-4849 vendor-advisory
- [debian-lts-announce] 20210211 [SECURITY] [DLA 2554-1] firejail security update mailing-list
- GLSA-202105-19 vendor-advisory