CVE-2025-66299 Security Sandbox Bypass with SSTI (Server Side Template Injection) in the Grav CMS
Authenticated editors can bypass the security sandbox via Server-Side Template Injection to execute arbitrary code on the server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-66299?
CVE-2025-66299 is a high-severity code injection vulnerability in Getgrav Grav, published on 1 Dec 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Grav is a file-based Web platform. Prior to 1.8.0-beta.27, Grav CMS is vulnerable to a Server-Side Template Injection (SSTI) that allows any authenticated user with editor permissions to execute arbitrary code on the remote server, bypassing the existing security sandbox. Since the security sandbox does not fully protect the Twig object, it is possible to interact with it (e.g., call methods, read/write attributes) through maliciously crafted Twig template directives injected into a web page. This allows an authenticated editor to add arbitrary functions to the Twig attribute system.twig.safe_filters, effectively bypassing the Grav CMS sandbox. This vulnerability is fixed in 1.8.0-beta.27.
Which versions are affected by CVE-2025-66299?
2 open source packages ship an affected version, including getgrav/grav. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
getgrav/grav Packagist | All versions | 1.8.0-beta.27 |
getgrav/grav Packagist | All versions | 1.8.0-beta.27 |
Products include Getgrav Grav.
How do I fix CVE-2025-66299?
Upgrade getgrav/grav to 1.8.0-beta.27 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2025-66299 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-66299 exists.
Other vulnerabilities in Getgrav Grav
- CVE-2023-34251 Grav Server Side Template Injection vulnerability
- CVE-2025-46199 Cross-site scripting in n/a
- CVE-2021-47812 GravCMS 1.10.7 - Arbitrary YAML Write/Update (Unauthenticated) (2)
- CVE-2025-66844 Grav may be vulnerable to SSRF attack via Twig Templates
- CVE-2022-2073 Code Injection in getgrav/grav
Sources
Also known as GHSA-gjc5-8cfh-653x.