CVE-2026-50592 in Znuny
Summary
by MITRE • 06/05/2026
In Znuny LTS before 6.5.21 and Znuny before 7.3.3, there is reflected XSS in
AdminCommunicationLog (aka the communication log administration view).
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Analysis
by VulDB Data Team • 06/05/2026
The vulnerability exists in Znuny LTS versions prior to 6.5.21 and Znuny versions prior to 7.3.3 within the AdminCommunicationLog functionality, which represents a reflected cross-site scripting weakness that allows remote attackers to inject malicious scripts into web applications. This flaw specifically affects the communication log administration view where user input is not properly sanitized before being rendered back to users. The reflected nature of this vulnerability means that malicious scripts are executed when a victim clicks on a specially crafted link containing the malicious payload, which is then reflected off the web server back to the user's browser. This type of vulnerability falls under CWE-79 which categorizes cross-site scripting flaws as weaknesses in web applications that allow attackers to inject client-side scripts into web pages viewed by other users. The vulnerability is particularly concerning in administrative interfaces where privileged users may be exposed to such attacks, potentially leading to unauthorized access to sensitive system information or operations.
The technical implementation of this flaw occurs when the application fails to properly validate and escape user-supplied input within the communication log administration view. When an attacker crafts a malicious URL containing script code and convinces a victim administrator to click on it, the script executes in the victim's browser within the context of the vulnerable application. This allows attackers to potentially steal session cookies, perform actions on behalf of the victim, or redirect them to malicious sites. The attack typically requires social engineering to get administrators to click on the malicious link, making it particularly dangerous in environments where administrators frequently interact with external links or reports. The vulnerability demonstrates poor input validation and output encoding practices that violate secure coding principles and standards established by organizations such as OWASP.
The operational impact of this reflected XSS vulnerability extends beyond simple script execution as it can enable attackers to escalate privileges within the administrative interface, potentially gaining access to sensitive customer data, system configuration information, or other administrative functions. Administrative users who are tricked into clicking malicious links could have their sessions hijacked, leading to complete system compromise. The vulnerability affects the integrity and confidentiality of the communication log functionality, which is critical for maintaining audit trails and monitoring system communications. Organizations using affected versions of Znuny may experience unauthorized access to their communication logs, which could contain sensitive business information, customer communications, or system diagnostics that attackers could exploit for further attacks. This vulnerability also impacts the availability of the system as attackers could potentially redirect administrators to malicious sites that could disrupt normal business operations or cause system instability.
The recommended mitigations for this vulnerability include immediate deployment of the security patches released in Znuny LTS 6.5.21 and Znuny 7.3.3, which address the reflected XSS issue through proper input validation and output encoding mechanisms. Organizations should implement comprehensive input sanitization routines that escape special characters in user-supplied data before rendering it in web pages, ensuring that all parameters passed to the AdminCommunicationLog view are properly validated. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be loaded. Security teams should also conduct regular security assessments of web applications to identify similar vulnerabilities and ensure that all input is properly sanitized. The mitigation strategy should also include user education to prevent social engineering attacks that exploit this vulnerability, as well as monitoring for suspicious activity in the communication log administration interface that could indicate exploitation attempts. Organizations should consider implementing web application firewalls to detect and block malicious payloads targeting this specific vulnerability while also ensuring that all web applications follow secure coding practices aligned with industry standards such as those defined in the OWASP Top Ten and NIST cybersecurity frameworks.