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GHSA-gq5c-rw37-g46c

LowCVSS 3.9 / 10
Published May 7, 2026·Last modified May 7, 2026
Affected Components(0)

No affected components available

Description

Summary

A Reflected Cross-Site Scripting (XSS) vulnerability exists in the fsNick cookie parameter. The application reflects the cookie's value directly into the HTML without sanitization.

Details

The fsNick cookie is rendered into the DOM without encoding. While the server does reject the modified session and forces a logout, the HTML containing the payload reaches the browser first. This lets the script execute immediately upon load, effectively beating the redirect.

PoC

  1. Log in to the application with any valid account.

    <img width="2078" height="302" alt="image" src="https://github.com/user-attachments/assets/d8a9a779-44e0-4a3e-839f-0a031868fbd5" />

  2. Capture any the GET request .

    <img width="1267" height="276" alt="image" src="https://github.com/user-attachments/assets/22e43f73-4f86-4cab-a074-7aba584a71ac" />

  3. Modify the value of "fsNick" with the following JavaScript: <script>alert(window.origin)</script>

  4. Send the modified request.

    <img width="1569" height="319" alt="image" src="https://github.com/user-attachments/assets/ade88db1-aadc-4c50-9e02-d09888067e98" />

  5. Result

    <img width="1217" height="771" alt="image" src="https://github.com/user-attachments/assets/5858fe9f-127a-4845-b484-5a7ef4ae2cb4" />

Impact

The payload executes before the session ends, which could potentially allow for a single unauthorized action before the logout.

Risk Scores
Base Score
3.9

The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a low impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
3.6

Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.

EPSS
0.10%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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Low severity
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