CVE-2026-15226 snapd snap-confine Sandbox Confinement Bypass via Omission of setuid Restriction in Seccomp Templates
Attackers can bypass snapd sandbox restrictions by creating setuid binaries, potentially escalating privileges within the confined environment.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-15226?
CVE-2026-15226 is a high-severity vulnerability in Canonical Ubuntu 16.04 LTS, published on 21 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-250
Which versions are affected by CVE-2026-15226?
How do I fix CVE-2026-15226?
Apply the vendor's patch.
Is CVE-2026-15226 being exploited?
There is no known exploitation of CVE-2026-15226 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-15226, GHSA-9pj8-7m3m-mh5h, UBUNTU-CVE-2026-15226.