CVE-2025-66305
Grav vulnerable to Denial of Service via Improper Input Handling in 'Supported' Parameter
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.
INFO
Published Date :
Dec. 1, 2025, 10:15 p.m.
Last Modified :
Dec. 3, 2025, 6:50 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Grav to version 1.8.0-beta.27.
- Validate user input in the Supported parameter.
- Avoid malformed values for the Supported parameter.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66305.
| URL | Resource |
|---|---|
| https://github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197ee | Patch |
| https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 | Exploit Vendor Advisory |
| https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66305 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66305
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66305 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66305 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Dec. 03, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:getgrav:grav:1.8.0:beta1:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta10:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta11:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta12:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta13:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta14:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta15:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta16:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta17:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta18:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta19:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta2:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta20:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta21:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta22:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta23:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta24:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta25:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta26:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta3:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta4:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta5:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta6:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta7:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta8:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:1.8.0:beta9:*:*:*:*:*:* *cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:* versions from (including) 1.7.48 up to (excluding) 1.8.0 Added Reference Type GitHub, Inc.: https://github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197ee Types: Patch Added Reference Type GitHub, Inc.: https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Dec. 02, 2025
Action Type Old Value New Value Added Reference https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 -
New CVE Received by [email protected]
Dec. 01, 2025
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CWE CWE-248 Added Reference https://github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197ee Added Reference https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6