CVE-2026-79774 Winter CMS before 1.2.13 Twig Sandbox Escape via SecurityPolicy
Authenticated users with template permissions can bypass Twig sandbox restrictions to execute arbitrary code and modify database records.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-79774?
CVE-2026-79774 is a critical code injection vulnerability in wintercms winter, published on 25 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Winter CMS versions before 1.2.13 contain an incomplete fix for a Twig sandbox escape vulnerability in System\\Twig\\SecurityPolicy that allows authenticated backend users with template-editing permissions to bypass sandbox restrictions. Attackers can exploit method forwarding through Eloquent models and query builders using methods like saveQuietly(), deleteQuietly(), increment(), decrement(), and newQuery() to read and modify arbitrary database records, execute arbitrary SQL, and achieve remote code execution by injecting PHP into template code sections.
Weakness: CWE-693
Which versions are affected by CVE-2026-79774?
2 open source packages ship an affected version, including winter/wn-system-module.
| Package | Affected | Fixed in |
|---|---|---|
winter/wn-system-module Packagist | From 1.2.7 | 1.2.13 |
winter/wn-system-module Packagist | From 1.2.7 | 1.2.13 |
How do I fix CVE-2026-79774?
Upgrade winter/wn-system-module to 1.2.13 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-79774 being exploited?
There is no known exploitation of CVE-2026-79774 in the wild and no public exploit code.
Sources
Also known as GHSA-8cfw-pcwh-v63w, GHSA-gw97-553p-fp3j.