Vulnerability · Published Jul 21, 2026 · Assigned by canonical
CVE-2026-15226snapd snap-confine Sandbox Confinement Bypass via Omission of setuid Restriction in Seccomp Templates
High 8.4
In plain English
A high-severity security flaw in snapd. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A sandbox confinement bypass vulnerability exists in Canonical snapd within its internal execution environment compiler (snap-confine). The default seccomp security templates generated by the engine to restrict system calls do not filter or reject process operations capable of creating or manipulating file execution flags with set-user-ID attributes. Consequently, an application running within a strictly confined snap environment can successfully compile or drop binaries and apply setuid properties to them. If a compromised or malicious process inside the snap sandbox executes these generated setuid binaries, it can potentially circumvent architectural sandboxing assumptions, drop intended restriction policies, or execute privileged actions inside the container namespace that should otherwise be strictly blocked. The vulnerability has been resolved by hardening the seccomp template engine to block the execution and creation of setuid executables by sandboxed snap processes.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | snapd | no fix listed | DEBIAN-CVE-2026-15226 |
| Debian:13 | snapd | no fix listed | DEBIAN-CVE-2026-15226 |
| Debian:14 | snapd | 2.76.3-1 | DEBIAN-CVE-2026-15226 |
| Ubuntu:22.04:LTS | snapd | 2.76+ubuntu22.04.1 | USN-8579-1 |
| Ubuntu:22.04:LTS | snapd | 2.76+ubuntu22.04.1 | UBUNTU-CVE-2026-15226 |
| Ubuntu:24.04:LTS | snapd | 2.76+ubuntu24.04.1 | USN-8579-1 |
| Ubuntu:24.04:LTS | snapd | 2.76+ubuntu24.04.1 | UBUNTU-CVE-2026-15226 |
| Ubuntu:26.04:LTS | snapd | 2.76+ubuntu26.04.3 | UBUNTU-CVE-2026-15226 |
| Ubuntu:26.04:LTS | snapd | 2.76+ubuntu26.04.3 | USN-8579-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| snapd | 0 – before 2.76.1 | |
| Canonical | Ubuntu 26.04 LTS | see references |
| Canonical | Ubuntu 24.04 LTS | see references |
| Canonical | Ubuntu 22.04 LTS | see references |
| Canonical | Ubuntu 20.04 LTS | see references |
| Canonical | Ubuntu 18.04 LTS | see references |
| Canonical | Ubuntu 16.04 LTS | see references |
Weakness: CWE-250 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
References
- https://ubuntu.com/security/CVE-2026-15226 vdb-entry, issue-tracking