CVE-2026-65448 in Anti Spam and list cleaner AcyChecker Plugin
Summary
by MITRE • 07/28/2026
Unauthenticated Cross Site Scripting (XSS) in Anti Spam and list cleaner – AcyChecker <= 1.8.1 versions.
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Analysis
by VulDB Data Team • 07/28/2026
The vulnerability under examination represents an unauthenticated cross site scripting flaw within the Anti Spam and list cleaner plugin known as AcyChecker, affecting all versions up to and including 1.8.1. This type of vulnerability falls squarely within the scope of CWE-79 which defines Cross-Site Scripting as a common web application security weakness where malicious scripts are injected into otherwise trusted websites. The flaw exists in the plugin's handling of user input within the administrative interface, specifically when processing data from external sources or user submissions without proper sanitization mechanisms.
The technical implementation of this vulnerability allows an attacker to inject malicious JavaScript code through parameters that are not adequately validated or escaped before being rendered back to users. In the context of AcyChecker, this typically occurs when processing email addresses, spam detection results, or list cleaning operations where user-provided data flows directly into HTML output contexts. The lack of input validation and output encoding creates an environment where attacker-controlled payloads can execute within the browser context of authenticated administrators who visit affected pages.
The operational impact of this vulnerability is significant as it enables attackers to perform unauthorized actions on behalf of system administrators without requiring authentication credentials. This opens the door to various malicious activities including session hijacking, data exfiltration, privilege escalation, and potential lateral movement within compromised systems. An attacker could craft malicious payloads that steal administrator cookies, redirect users to phishing sites, or inject additional malware into the target environment. The vulnerability's persistence across multiple versions suggests a fundamental flaw in the plugin's input handling architecture rather than a one-time coding error.
Mitigation strategies should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application codebase. The recommended approach includes applying proper HTML escaping to all user-controllable data before rendering it within web pages, implementing Content Security Policy headers to limit script execution, and conducting regular security audits of input processing functions. Organizations should immediately update to version 1.8.2 or later where this vulnerability has been patched according to industry best practices for vulnerability management. The ATT&CK framework categorizes this vulnerability under T1566 which covers Phishing techniques, specifically targeting the credential access and persistence phases through web-based attacks that leverage XSS flaws in web applications.