CVE-2025-66299
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-01

Last updated on: 2025-12-03

Assigner: GitHub, Inc.

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.
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Meta Information
Published
2025-12-01
Last Modified
2025-12-03
Generated
2026-05-07
AI Q&A
2025-12-01
EPSS Evaluated
2026-05-05
NVD
Affected Vendors & Products
Showing 27 associated CPEs
Vendor Product Version / Range
getgrav grav to 1.8.0 (exc)
getgrav grav 1.8.0
getgrav grav 1.8.0
getgrav grav 1.8.0
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getgrav grav 1.8.0
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getgrav grav 1.8.0
getgrav grav 1.8.0
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getgrav grav 1.8.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-94 The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
CWE-1336 The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a Server-Side Template Injection (SSTI) in Grav CMS versions prior to 1.8.0-beta.27. It allows any authenticated user with editor permissions to execute arbitrary code on the remote server by bypassing the existing security sandbox. The issue arises because the sandbox does not fully protect the Twig object, enabling maliciously crafted Twig template directives to interact with it, such as calling methods or reading/writing attributes. This lets an attacker add arbitrary functions to the Twig attribute system, effectively bypassing the Grav CMS sandbox.


How can this vulnerability impact me? :

This vulnerability can have severe impacts as it allows an authenticated editor to execute arbitrary code on the server. This can lead to full compromise of the server, including unauthorized access to sensitive data, modification or deletion of data, disruption of services, and potentially using the server as a pivot point for further attacks.


What immediate steps should I take to mitigate this vulnerability?

Upgrade Grav CMS to version 1.8.0-beta.27 or later, as this version contains the fix for the Server-Side Template Injection vulnerability. Additionally, restrict editor permissions to trusted users only until the upgrade is applied.


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0/70
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