CVE-2026-4653 in Block, Suspend, Report for BuddyPress Plugin
Summary
by MITRE • 07/09/2026
The Block, Suspend, Report for BuddyPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'link' parameter in versions up to and including 3.6.4. This is due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with subscriber-level access and above to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 07/09/2026
The Block Suspend Report for BuddyPress plugin presents a critical stored cross-site scripting vulnerability that affects WordPress installations running versions up to and including 3.6.4. This security flaw resides within the plugin's handling of the 'link' parameter, which fails to implement proper input sanitization measures. The vulnerability operates at the intersection of insufficient data validation and inadequate output escaping mechanisms, creating a persistent threat vector that can be exploited by malicious actors with subscriber-level privileges or higher. The technical implementation lacks proper sanitization routines that would normally filter or escape potentially dangerous input before it is stored in the database and subsequently rendered in user-facing pages.
The operational impact of this vulnerability extends beyond simple script injection, as it enables authenticated attackers to establish persistent malicious presence within the WordPress environment. When a victim accesses a page containing the injected script, the malicious code executes within the context of the victim's browser session, potentially leading to session hijacking, credential theft, or further exploitation of the compromised user account. This stored XSS vulnerability is particularly dangerous because the injected scripts remain persistent in the database until manually removed, allowing attackers to maintain access and execute malicious payloads across multiple user sessions. The vulnerability affects all users who have access to pages where the malicious link parameter might be processed, making it a significant threat to community platforms that rely heavily on user-generated content and social interactions.
The security implications of this vulnerability align with CWE-79 which describes improper neutralization of input during web page generation, specifically addressing stored cross-site scripting conditions. From an ATT&CK framework perspective, this represents a technique categorized under T1566.002 - Phishing: Spearphishing Attachment, where attackers can establish malicious web content that executes when users navigate to affected pages. The vulnerability also demonstrates characteristics of T1071.004 - Application Layer Protocol: DNS, as the malicious scripts could potentially be used to exfiltrate data or redirect users to malicious domains. Additionally, this flaw represents a weakness in the principle of least privilege since it allows lower-privilege users to execute code that should only be accessible to administrators or privileged system components.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements. The most direct solution involves implementing proper input sanitization using WordPress's built-in esc_attr() or similar escaping functions before storing user-provided data in the database. The plugin developers should also implement strict validation routines that filter out potentially dangerous characters and patterns from URL inputs, particularly those that could be used to construct malicious javascript: or data: URI schemes. Users should immediately upgrade to the latest version of the plugin where this vulnerability has been patched, as the fix typically involves implementing comprehensive input validation and output escaping mechanisms. Organizations should also consider implementing additional security measures such as content security policies that limit script execution permissions and regular security audits of third-party plugins to identify similar vulnerabilities in other components of their WordPress infrastructure.