Grav Admin Plugin vulnerable to Cross-Site Scripting (XSS) Stored endpoint /admin/config/site parameter data[taxonomies]

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.8 · CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N · score source

EPSS

• CVE-2025-66308: 0.23% estimated exploitation activity in the next 30 days; percentile 13.80 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. --- Details Vulnerable Endpoint: POST /admin/config/site Parameter: data[taxonomies] The application does not properly validate or sanitize input in the data[taxonomies] field. As a result, an attacker can inject JavaScript code, which is stored in the site configuration and later rendered in the administrative interface or site output, causing automatic execution in the user's browser. --- PoC Payload: "<scriptalert('XSS-PoC')</script Steps to Reproduce: 1. Log in to the Grav Admin Panel with sufficient permissions to modify site configuration. 2. Navigate to…

Published by the source

2 Dec 2025, 01:23 UTC

Last modified by the source

2 Dec 2025, 01:23 UTC

Source last checked

26 Oct 2026, 14:35 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-gqxx-248x-g29f

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# Patch Next advisory brief: CVE-2025-66308

Advisory: Grav Admin Plugin vulnerable to Cross-Site Scripting (XSS) Stored endpoint `/admin/config/site` parameter `data[taxonomies]`
IDs: CVE-2025-66308, GHSA-gqxx-248x-g29f
Record: https://patchnext.com/advisories/cve-2025-66308 (revision 1, source checked 26 Oct 2026, 14:35 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: getgrav/grav 1.8.0-beta.27. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist getgrav/grav: affected < 1.8.0-beta.27; fixed in 1.8.0-beta.27

## Suggested inspection (read-only)
- Packagist getgrav/grav: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on getgrav/grav.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-gqxx-248x-g29f (GitHub-reviewed advisory GHSA-gqxx-248x-g29f lists affected ranges: Packagist getgrav/grav >=0 <1.8.0-beta.27)

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