{"cve":"CVE-2025-66305","nvd":{"published":"2025-12-01T22:15:50.250","modified":"2026-06-17T09:56:38.860","status":"Analyzed","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.","cvss_v4":{"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","score":6.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","score":4.9},"cwes":["CWE-248"],"references":["https://github.com/getgrav/grav/commit/ed640a13143c4177af013cf001969ed2c5e197ee","https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6","https://github.com/getgrav/grav/security/advisories/GHSA-m8vh-v6r6-w7p6"],"products":["getgrav:grav"],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-66305","score":0.00414,"percentile":0.35675,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}