CVE-2026-8933Public exploit

Root escalation via symlink-following bootstrap file creation

Published Jul 21, 2026 · Updated Jul 21, 2026

Local privilege escalation in Canonical snapd 2.75.0 through 2.76.0 allows local users to execute arbitrary code as root. In set-capabilities builds, snap-confine creates its bootstrap /tmp/snap.rootfs_XXXXXX directory and replicated files under the caller's ownership before changing them to root, while open() follows attacker-planted symlinks. Winning both races lets a local unprivileged user create a writable udev rule in /run/udev/rules.d and have systemd-udevd run a command as root; set-user-ID-root builds are unaffected.

CVSS severity7.8
High
EPSS probability0.21%
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 2.75.0 through 2.76.0 allows local users to execute arbitrary code as root. In set-capabilities builds, snap-confine creates its bootstrap /tmp/snap.rootfs_XXXXXX directory and replicated files under the caller's ownership before changing them to root, while open() follows attacker-planted symlinks. Winning both races lets a local unprivileged user create a writable udev rule in /run/udev/rules.d and have systemd-udevd run a command as root; set-user-ID-root builds are unaffected.

The record

CVE
CVE-2026-8933
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Canonical
Product
Ubuntu 22.04 LTS
Classifications
CWE-250, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 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 24.04 LTSAffected versions are unavailable in this record.
Canonical · Ubuntu 26.04 LTSAffected versions are unavailable in this record.
Canonical · snapdversion=2.75.0 <2.76.1

Published CVSS scores

7.8CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-250Execution with Unnecessary Privileges
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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