CVE-2026-3888Public exploit

Root privilege escalation via private temporary-directory recreation

Published Mar 17, 2026 · Updated Mar 17, 2026

Local privilege escalation in Canonical snapd before 2.75.1 allows local users to gain root access through a recreated private temporary directory. After systemd-tmpfiles deletes the stale /tmp/.snap directory, snap-confine bind-mounts attacker-controlled files as root during sandbox setup. Exploitation requires a low-privileged local account, automatic cleanup of the directory, and winning the sandbox-initialization race; success grants full host control.

CVSS severity7.8
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in Canonical snapd before 2.75.1 allows local users to gain root access through a recreated private temporary directory. After systemd-tmpfiles deletes the stale /tmp/.snap directory, snap-confine bind-mounts attacker-controlled files as root during sandbox setup. Exploitation requires a low-privileged local account, automatic cleanup of the directory, and winning the sandbox-initialization race; success grants full host control.

The record

CVE
CVE-2026-3888
Published
Mar 17, 2026
Updated
Mar 17, 2026
Vendor
Canonical
Product
Ubuntu 22.04 LTS
Classifications
CWE-268, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Canonical · Ubuntu 22.04 LTSAffected versions are unavailable in this record.
Canonical · Ubuntu 18.04 LTSAffected versions are unavailable in this record.
Canonical · Ubuntu 24.04 LTSAffected versions are unavailable in this record.
Canonical · Ubuntu 16.04 LTSAffected versions are unavailable in this record.
Canonical · Ubuntu 20.04 LTSAffected versions are unavailable in this record.
Canonical · snapdversion=0 <2.75.1

Published CVSS scores

7.8Canonical Ltd.CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-268Privilege Chaining
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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