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.
Conclusion & alert: CVE-2026-3888 is rated Low Risk (31.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-18 | — | 0.01% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.1 | 6.0 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-3888 not yet assigned priority: Debian including 1 source packages (snapd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. | https://security-tracker.debian.org/tracker/CVE-2026-3888 |
ubuntu
|
high | CVE-2026-3888 high priority: Ubuntu including 1 source packages (snapd), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): released 6, pending 1. | https://ubuntu.com/security/CVE-2026-3888 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| canonical | ubuntu_linux | 16.04 | cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* |
| canonical | ubuntu_linux | 18.04 | cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* |
| canonical | ubuntu_linux | 20.04 | cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* |
| canonical | ubuntu_linux | 22.04 | cpe:2.3:o:canonical:ubuntu_linux:22.04:*:*:*:lts:*:*:* |
| canonical | ubuntu_linux | 24.04 | cpe:2.3:o:canonical:ubuntu_linux:24.04:*:*:*:lts:*:*:* |
| URL | Tags |
|---|---|
| https://blog.qualys.com/vulnerabilities-threat-research/2026/03/17/cve-2026-3888-important-snap-flaw-enables-local-privilege-escalation-to-root | Mitigation Third Party Advisory |
| https://cdn2.qualys.com/advisory/2026/03/17/snap-confine-systemd-tmpfiles.txt | Third Party Advisory |
| https://discourse.ubuntu.com/t/snapd-local-privilege-escalation-cve-2026-3888 | Mitigation Third Party Advisory |
| https://ubuntu.com/security/CVE-2026-3888 | Third Party Advisory |
| https://ubuntu.com/security/notices/USN-8102-1 | Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2026/03/18/1 | Mailing List Third Party Advisory |