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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-m8vh-v6r6-w7p6 Grav vulnerable to Denial of Service via Improper Input Handling in 'Supported' Parameter
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 03 Dec 2025 19:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*
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:beta1:*:*:*:*:*:*
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:beta2:*:*:*:*:*:*
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:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}


Tue, 02 Dec 2025 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 02 Dec 2025 12:30:00 +0000

Type Values Removed Values Added
First Time appeared Getgrav
Getgrav grav
Vendors & Products Getgrav
Getgrav grav

Mon, 01 Dec 2025 21:45:00 +0000

Type Values Removed Values 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.
Title Grav vulnerable to Denial of Service via Improper Input Handling in 'Supported' Parameter
Weaknesses CWE-248
References
Metrics cvssV4_0

{'score': 6.9, 'vector': '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-12-02T20:14:21.770Z

Reserved: 2025-11-26T23:11:46.395Z

Link: CVE-2025-66305

cve-icon Vulnrichment

Updated: 2025-12-02T20:14:02.932Z

cve-icon NVD

Status : Analyzed

Published: 2025-12-01T22:15:50.250

Modified: 2025-12-03T18:50:11.847

Link: CVE-2025-66305

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-02T11:58:50Z

Weaknesses