What is the CVSS score of CVE-2025-66309?

CVE-2025-66309 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Grav Plugin Admin are affected by CVE-2025-66309?

Organizations using This admin should be aware of moderate risk from CVE-2025-66309, a cross-site scripting vulnerability rated CVSS 6.1.. A patch is available.

Is there a public PoC exploit available for CVE-2025-66309?

Yes, a public proof-of-concept exploit is available for CVE-2025-66309. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2025-66309?

Within 30 days: Identify affected systems running plugin for Grav is an HTML user interface that provides a co and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Grav Plugin Admin CVE-2025-66309

EUVD-2025-200101 MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2025-12-01 security-advisories@github.com

GHSA-65mj-f7p4-wggq

XSS Grav Plugin Admin

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

EUVD ID Assigned

Mar 15, 2026 - 13:34 euvd

EUVD-2025-200101

Analysis Generated

Mar 15, 2026 - 13:34 vuln.today

Patch released

Mar 15, 2026 - 13:34 nvd

Patch available

PoC Detected

Dec 03, 2025 - 21:56 vuln.today

Public exploit code

CVE Published

Dec 01, 2025 - 22:15 nvd

MEDIUM 6.1

DescriptionGitHub Advisory

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Reflected Cross-Site Scripting (XSS) vulnerability was identified in the /admin/pages/[page] endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[header][content][items] parameter. This vulnerability is fixed in 1.11.0-beta.1.

Analysis

Technical ContextAI

Cross-site scripting (XSS) allows injection of client-side scripts into web pages viewed by other users due to insufficient output encoding.

RemediationAI

A vendor patch is available — apply it immediately. Encode all user-supplied output contextually (HTML, JS, URL). Implement Content Security Policy (CSP) headers. Use HTTPOnly and Secure cookie flags.