CVE-2026-3888: Local Privilege Escalation in snapd

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-17 · updated 2026-06-17
Weakness: CWE-268

Description

Local privilege escalation in snapd on Linux allows local attackers to get root privilege by re-creating snap's private /tmp directory when systemd-tmpfiles is configured to automatically clean up this directory. This issue affects Ubuntu 16.04 LTS, 18.04 LTS, 20.04 LTS, 22.04 LTS, and 24.04 LTS.

Affected products

Canonical Ubuntu Linux: 16.04, 18.04, 20.04, 22.04, 24.04

References

https://blog.qualys.com/vulnerabilities-threat-research/2026/03/17/cve-2026-3888-important-snap-flaw-enables-local-privilege-escalation-to-root
https://cdn2.qualys.com/advisory/2026/03/17/snap-confine-systemd-tmpfiles.txt
https://discourse.ubuntu.com/t/snapd-local-privilege-escalation-cve-2026-3888
https://ubuntu.com/security/CVE-2026-3888
https://ubuntu.com/security/notices/USN-8102-1
http://www.openwall.com/lists/oss-security/2026/03/18/1

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