Vulnerability in Getgrav Grav
CVE-2025-66305
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (30.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Getgrav Grav — versions 1.8.0, < 1.8.0-beta.27
Weakness classification (CWE)
References
- github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6 (Exploit, Vendor Advisory)
- github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197ee (Patch)
Frequently asked questions
- What is CVE-2025-66305?
- CVE-2025-66305 is a medium-severity vulnerability in Getgrav Grav, classified under CWE-248. CVSS score: 4.9/10. Published 2025-12-01.
- How severe is CVE-2025-66305?
- Medium severity. CVSS v3 base score is 4.9 out of 10.