CVE-2025-66305

Name: CVE-2025-66305
Creator: NVD / NIST
Published: 2025-12-01T22:15:50.25+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.33%

Last modified Jun 17, 2026

CVE-2025-66305 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a Denial of Service (DoS) vulnerability was identified in the "Languages" submenu of the Grav admin configuration panel (/admin/config/system). EPSS estimates a 0.33% chance of exploitation in the next 30 days.

Description

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a Denial of Service (DoS) vulnerability was identified in the "Languages" submenu of the Grav admin configuration panel (/admin/config/system). Specifically, the Supported parameter fails to properly validate user input. If a malformed value is inserted—such as a single forward slash (/) or an XSS test string—it causes a fatal regular expression parsing error on the server. This leads to application-wide failure due to the use of the preg_match() function with an improperly constructed regular expression, resulting in an error. Once triggered, the site becomes completely unavailable to all users. This vulnerability is fixed in 1.8.0-beta.27.

Metrics

CVSS 3.1

4.9/10

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

CVSS 4.0

6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.33%

24.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-248

Affected Software

Vendor	Product	Versions	Update
Getgrav	Grav	>= 1.7.48, < 1.8.0	—
Getgrav	Grav	1.8.0	Beta1

References

https://github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197eePatch
https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6Exploit, Vendor Advisory
https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6Exploit, Vendor Advisory

Timeline

Published: Dec 1, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-66305?

How severe is CVE-2025-66305?

CVE-2025-66305 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66305?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-66305?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST