CVE-2026-93485 in WordPress
Summary
by MITRE • 09/18/2026
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Automattic WordPress core allows DOM-Based XSS.
This issue affects WordPress versions 7.1 before 7.1.1; 7.0 through 7.0.4; 6.9 through 6.9.7; 6.8 through 6.8.8; 6.7 through 6.7.7; 6.6 through 6.6.7; 6.5 through 6.5.10; 6.4 through 6.4.10; 6.3 through 6.3.10; 6.2 through 6.2.11; 6.1 through 6.1.12; 6.0 through 6.0.14; 5.9 through 5.9.16; 5.8 through 5.8.15; 5.7 through 5.7.17; 5.6 through 5.6.19; 5.5 through 5.5.20; 5.4 through 5.4.21; 5.3 through 5.3.23; 5.2 through 5.2.26; 5.1 through 5.1.24; 5.0 through 5.0.27; 4.9 through 4.9.31; 4.8 through 4.8.30; and 4.7 through 4.7.35.
The Unauthenticated Stored XSS vulnerability in the WordPress core can be reproduced on a default WordPress installation. Comment moderation is disabled by default, and the requirement for commenters to have a previously approved comment can be bypassed.
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Analysis
by VulDB Data Team • 09/18/2026
This security advisory addresses a critical cross-site scripting (XSS) vulnerability within Automattic's WordPress content management system, specifically classified as an improper neutralization of input during web page generation. The flaw manifests as a DOM-based XSS attack vector that allows malicious scripts to execute in the context of a victim user's browser session. This issue impacts a vast range of legacy and current versions, spanning from WordPress 4.7 through version 7.1, with specific patches available for versions prior to 7.1.1, as well as all minor releases down to 4.7.x. The breadth of affected versions underscores the systemic nature of the input validation failure within the core codebase rather than an isolated plugin or theme defect.
The technical root cause lies in how WordPress processes and renders user-supplied data during page generation without adequate sanitization. In a DOM-based XSS scenario, the vulnerability is triggered not by server-side execution but through client-side script processing where untrusted data is written to the Document Object Model (DOM) using unsafe methods such as innerHTML or document.write. When an attacker injects malicious JavaScript payloads into input fields that are subsequently rendered on the page without proper encoding, the browser executes this code upon loading the affected view. This bypasses traditional server-side security controls because the exploitation occurs entirely within the client's environment after the data has been received and processed by the frontend logic.
A significant factor contributing to the severity of this vulnerability is its unauthenticated nature combined with stored persistence characteristics in certain configurations. The description notes that on a default WordPress installation, comment moderation is disabled by default, meaning user-submitted content appears immediately without administrative review. Furthermore, the requirement for new commenters to have a previously approved comment can be bypassed under specific conditions or through automated submission techniques. This allows an attacker to inject malicious payloads directly into public-facing pages via comments or other input vectors accessible to unauthenticated users. Once stored in the database and rendered on subsequent page loads, this constitutes a persistent threat that affects every visitor who views the compromised content.
The operational impact of this vulnerability is severe due to its potential for widespread exploitation. Successful exploitation enables attackers to perform session hijacking by stealing authentication cookies or tokens, leading to unauthorized access to administrator accounts if they view the malicious payload. It also facilitates phishing attacks where the attacker can inject fake login forms or deceptive messages that appear legitimate because they originate from a trusted domain. Additionally, this vulnerability can be used to deface websites, redirect users to malicious sites, or spread malware by exploiting browser vulnerabilities through injected scripts. The ability to execute arbitrary JavaScript grants attackers full control over the DOM, allowing them to manipulate page content, capture keystrokes, and exfiltrate sensitive data from authenticated sessions.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation (Cross-site Scripting). The specific mechanism falls under DOM-based XSS, which is distinct from reflected or stored server-side XSS because the payload execution relies on client-side JavaScript processing untrusted data. In terms of offensive security frameworks, this aligns with MITRE ATT&CK technique T1059: Command and Control via Application Layer Protocol, specifically when used for initial access through phishing components embedded in web pages, or more accurately T1189: Drive-by Compromise if the script triggers further malware downloads. The unauthenticated aspect places it within the Initial Access phase of an attack lifecycle, while the stored nature allows for persistent presence without repeated interaction from the attacker after the initial injection.
Mitigation strategies must prioritize immediate software updates as the primary defense vector. Administrators running any version of WordPress between 4.7 and 6.x should upgrade to the latest patched release immediately, ensuring they move beyond the vulnerable ranges specified in the advisory. For those on versions prior to 5.0 or other legacy branches that may no longer receive standard security updates, upgrading is critical as these older codebases lack modern input sanitization libraries like wp_kses and esc_html which are designed specifically to prevent XSS by encoding special characters before rendering them into HTML contexts. If immediate patching is not feasible due to compatibility constraints with custom themes or plugins, temporary mitigations include enabling strict comment moderation settings through the WordPress dashboard to require administrative approval for all new comments, thereby preventing unauthenticated users from storing malicious payloads in the database.
Additional defensive measures involve implementing a Web Application Firewall (WAF) configured to detect and block common XSS patterns in HTTP request parameters, particularly those targeting comment forms or user profile fields. Content Security Policy (CSP) headers should be deployed to restrict the sources from which scripts can be executed, effectively neutralizing inline script injection even if it occurs. Regular security audits of custom code are essential to ensure that any developer-written functions handling user input adhere to strict sanitization standards. Finally, educating site administrators about the risks of unauthenticated stored XSS and ensuring that default configurations like comment moderation remain enabled or manually enforced can significantly reduce the attack surface available to opportunistic attackers exploiting this widespread vulnerability.