CVE-2026-3888 | Local Privilege Escalation in snapd

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.

Published: 2026-03-17 Last update: 2026-06-04 Assigner: [email protected] Source: [email protected]

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.

Exploit prediction scoring system (EPSS) score for CVE-2026-3888

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)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-3888

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.1 6.0 [email protected]

Weakness enumeration for CVE-2026-3888

OS Trackers for CVE-2026-3888

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

Affected software / configurations for 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:*:*:*

References for CVE-2026-3888

cvelogic Threat Intelligence