CVE-2025-66308: Getgrav/grav Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gqxx-248x-g29f",
  "modified" : "2025-12-02T01:23:19Z",
  "published" : "2025-12-02T01:23:19Z",
  "aliases" : [ "CVE-2025-66308" ],
  "summary" : "Grav Admin Plugin vulnerable to Cross-Site Scripting (XSS) Stored endpoint `/admin/config/site` parameter `data[taxonomies]`",
  "details" : "## Summary\n\nA 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.\n\n---\n\n## Details\n\n**Vulnerable Endpoint:** `POST /admin/config/site`  \n**Parameter:** `data[taxonomies]`\n\nThe 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.\n\n---\n\n## PoC\n\n**Payload:**\n\n`\"><script>alert('XSS-PoC')</script>`\n\n### Steps to Reproduce:\n\n1. Log in to the _Grav_ Admin Panel with sufficient permissions to modify site configuration.\n    \n2. Navigate to **Configuration > Site**.\n    \n3. In the **Taxonomies Types** field (which maps to `data[taxonomies]`), insert the payload above:\n          \n    `\"><script>alert('XSS-PoC')</script>`\n    \n4. Save the configuration.\n\n<img width=\"1897\" height=\"628\" alt=\"Pasted image 20250718195942\" src=\"https://github.com/user-attachments/assets/2035fcaa-34fc-494c-a7ca-7c1e1f34b057\" />\n    \n5. Go on Pages and click on one of them\n\n<img width=\"932\" height=\"587\" alt=\"Pasted image 20250718200306\" src=\"https://github.com/user-attachments/assets/3c1995ba-2581-4e27-ae9d-a17e2eeb5b57\" />\n    \n6. The stored payload is executed immediately in the browser, confirming the Stored XSS vulnerability.\n\n<img width=\"1204\" height=\"377\" alt=\"Pasted image 20250718200353\" src=\"https://github.com/user-attachments/assets/ad8ea7ea-603f-4b84-aa5a-120de0cb56ce\" />\n    \n7. The HTTP request submitted during this process contains the vulnerable parameter and payload:\n    \n<img width=\"757\" height=\"675\" alt=\"Pasted image 20250718200445\" src=\"https://github.com/user-attachments/assets/fbbe2b76-00eb-4426-8ddd-5cde2cc65d77\" />\n\n---\n\n## Impact\n\nStored XSS attacks can lead to severe consequences, including:\n\n- **Session hijacking:** Stealing cookies or authentication tokens to impersonate users\n    \n- **Credential theft:** Harvesting usernames and passwords using malicious scripts\n    \n- **Malware delivery:** Distributing unwanted or harmful code to victims\n    \n- **Privilege escalation:** Compromising administrative users through persistent scripts\n    \n- **Data manipulation or defacement:** Changing or disrupting site content\n    \n- **Reputation damage:** Eroding trust among site users and administrators\n    \n\n---\n\n## Discoverer\n\n[Marcelo Queiroz](www.linkedin.com/in/marceloqueirozjr) \n\nby [CVE-Hunters](https://github.com/Sec-Dojo-Cyber-House/cve-hunters)",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "getgrav/grav"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.0-beta.27"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/getgrav/grav/security/advisories/GHSA-gqxx-248x-g29f"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-66308"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getgrav/grav-plugin-admin/commit/99f653296504f1d6408510dd2f6f20a45a26f9b0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/getgrav/grav"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-02T01:23:19Z",
    "nvd_published_at" : "2025-12-01T22:15:50Z"
  }
}