Description

Unauthenticated Cross Site Scripting (XSS) in EmbedPress <= 4.5.6 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.1",
  "pubDate": "2026-08-06T15:17:12.950Z",
  "pubdate": "2026-08-06T15:17:12.950Z",
  "executiveSummary": "An unauthenticated Cross-Site Scripting (XSS) vulnerability has been identified in the EmbedPress plugin affecting versions up to and including 4.5.6. This security flaw enables remote, unauthenticated attackers to inject malicious client-side scripts, typically JavaScript, into legitimate web pages rendered by the affected software. When unsuspecting users visit the compromised page, the injected payload executes within the context of their browser session. The primary risk implication includes session hijacking, unauthorized access to sensitive user data, cookie theft, and potential redirection to malicious external domains. Exploitation requires network access to the target WordPress installation and relies on the victim interacting with or viewing the maliciously crafted embed component. Because the vulnerability is unauthenticated, threat actors do not require prior access credentials to target vulnerable endpoints, significantly increasing the attack surface. Remediation requires updating the EmbedPress plugin to a version subsequent to 4.5.6 where input sanitization and output encoding mechanisms are properly enforced.",
  "technicalDetails": "The vulnerability resides within the input handling and output rendering mechanisms of the EmbedPress plugin affecting versions <= 4.5.6. Specifically, the software fails to properly sanitize or validate user-supplied parameters before echoing them back into the Document Object Model (DOM) during the rendering of embedded content. This lack of robust contextual output encoding allows an attacker to bypass security boundaries and inject arbitrary HTML markup containing executable JavaScript payloads.\nExploitation occurs over the network without requiring any authentication or specific privilege levels from the attacker. The attack flow typically proceeds as follows: First, the threat actor crafts a malicious URL or payload containing embedded script tags or event handlers tailored to exploit the vulnerable input parameter within EmbedPress. Second, the attacker induces a victim to load the crafted resource or interact with the vulnerable embed functionality on the target WordPress site. Third, the unvalidated input is processed by the vulnerable component and reflected directly into the HTTP response delivered to the client browser. Finally, the browser parses the response, executing the injected script within the security context of the victim's active session, allowing the execution of arbitrary script logic such as accessing document.cookie or performing unauthorized actions via the WordPress REST API or administrative AJAX endpoints if the victim possesses elevated privileges."
}