CVE-2026-22199 in wpDiscuz
Summary
by MITRE • 03/13/2026
wpDiscuz before 7.6.47 contains a vote manipulation vulnerability that allows attackers to manipulate comment votes by obtaining fresh nonces and bypassing rate limiting through client-controlled headers. Attackers can vary User-Agent headers to reset rate limits, request nonces from the unauthenticated wpdGetNonce endpoint, and vote multiple times using IP rotation or reverse proxy header manipulation.
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Analysis
by VulDB Data Team • 03/20/2026
The wpDiscuz plugin for wordpress presents a critical vote manipulation vulnerability that undermines the integrity of comment voting systems. This vulnerability affects versions prior to 7.6.47 and represents a significant weakness in the plugin's authentication and rate limiting mechanisms. The flaw enables attackers to systematically manipulate comment votes through sophisticated techniques that exploit the plugin's nonce handling and client identification methods. The vulnerability specifically targets the core functionality that governs how user votes are processed and validated within the comment system.
The technical implementation of this vulnerability stems from the plugin's insufficient validation of client requests and weak nonce management. Attackers can exploit the unauthenticated wpdGetNonce endpoint to obtain fresh nonces without proper authentication checks, effectively bypassing the intended security controls. This endpoint should require proper authentication or at least implement robust rate limiting to prevent abuse. The vulnerability is exacerbated by the plugin's reliance on client-controlled headers for identifying users, particularly the User-Agent header, which attackers can manipulate to reset rate limiting mechanisms. The system's failure to properly validate or track client identity through multiple headers creates opportunities for repeated voting attempts.
The operational impact of this vulnerability extends beyond simple vote manipulation to potentially affect the credibility and integrity of entire comment systems. Attackers can execute coordinated voting campaigns that skew comment rankings and influence user perception of content quality or popularity. The ability to rotate IP addresses or manipulate reverse proxy headers allows attackers to circumvent typical IP-based rate limiting controls, making detection and prevention significantly more challenging. This vulnerability can be exploited at scale, potentially enabling attackers to manipulate the visibility of specific comments or topics within a wordpress installation. The impact is particularly severe in environments where comment voting drives content curation or user engagement metrics.
Security mitigations for this vulnerability should focus on strengthening nonce validation mechanisms and implementing comprehensive rate limiting that is not solely dependent on client-controlled headers. The wpDiscuz plugin should require proper authentication for nonce generation endpoints and implement robust session management to track legitimate user activity. Organizations should ensure that rate limiting mechanisms are based on multiple factors including IP address, user agent, and request patterns rather than relying on single header values. The implementation should follow established security practices outlined in the CWE database, specifically addressing CWE-352 Cross-Site Request Forgery and CWE-305 Authentication Issues. Additionally, security controls should align with ATT&CK framework techniques such as T1078 Valid Accounts and T1566 Phishing to prevent unauthorized access and manipulation of voting systems. Regular security audits and monitoring of comment voting patterns should be implemented to detect potential abuse of the system.