CVE-2025-66299

HIGH
Published Dec 1, 2025 Modified Dec 3, 2025 CWE-94 CWE-1336

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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CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-94 CWE-94
CWE-1336 CWE-1336

Affected Products

Vendor Product
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav
getgrav grav

References

Frequently Asked Questions

What is CVE-2025-66299? +
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. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2025-66299? +
CVE-2025-66299 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2025-66299? +
CVE-2025-66299 affects products from getgrav, specifically: grav. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2025-66299? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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