# 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.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`)
- **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:** Yes
- **Published:** 21 Jul 2026
- **Updated:** 22 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-15226, GHSA-9pj8-7m3m-mh5h, UBUNTU-CVE-2026-15226

## 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 (Execution with Unnecessary Privileges)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15226 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-15226 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 16.04 LTS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15226/ (Markdown: https://insights.sbomify.com/CVE-2026-15226/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15226
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15226
- OSV: https://osv.dev/vulnerability/CVE-2026-15226

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15226/
Summaries are generated and may contain mistakes; the official description above is the record.