Snapd setuid Bypass via Snap-Confine Seccomp
CVE-2026-15226 Published on July 21, 2026
snapd snap-confine Sandbox Confinement Bypass via Omission of setuid Restriction in Seccomp Templates
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.
Vulnerability Analysis
CVE-2026-15226 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
Execution with Unnecessary Privileges
The software performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.