Description

Author Cross Site Scripting (XSS) in Subscribe to Comments <= 2.3.1 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.9",
  "pubDate": "2026-08-06T15:17:23.547Z",
  "pubdate": "2026-08-06T15:17:23.547Z",
  "executiveSummary": "An Author Cross-Site Scripting (XSS) vulnerability has been identified in the Subscribe to Comments plugin, affecting versions up to and including 2.3.1. This security flaw enables authenticated users with Author-level privileges to inject malicious scripts, typically in the form of JavaScript, into the application parameters or input fields handled by the vulnerable plugin. The primary impact of this vulnerability is the execution of arbitrary script code in the context of a victim's browser session, which can lead to session hijacking, credential theft, or unauthorized modification of content and administrative actions if an administrative user interacts with the payload.\nThe affected system is the Subscribe to Comments plugin up to version 2.3.1. The risk implication is moderate to high, depending on the privileges of the targeted user interacting with the payload, as successful exploitation bridges the trust boundary between the application and the user's browser. The attacker capabilities require possessing Author-level access within the target application to inject the payload. Exploitation requirements mandate that the attacker has authenticated credentials with sufficient privileges to submit input that is subsequently rendered improperly by the vulnerable software.",
  "technicalDetails": "The vulnerability stems from insufficient input sanitization and output encoding within the Subscribe to Comments plugin up to version 2.3.1. Specifically, the software fails to adequately filter user-supplied data before rendering it back to the interface, allowing specially crafted input containing HTML or JavaScript vectors to be stored or reflected improperly.\nThe vulnerable component resides within the input handling and parameter processing functions of the Subscribe to Comments plugin. Because the affected versions permit users with Author-level privileges to interact with these vulnerable parameters, an attacker authenticated as an Author can supply a malicious payload designed to execute arbitrary client-side code.\nThe attack flow proceeds as follows: First, the authenticated attacker with Author privileges crafts an HTTP request containing a malicious script payload targeting the vulnerable input fields or parameters of the Subscribe to Comments plugin. Second, the application accepts this input and stores or processes it without applying proper contextual output encoding or strict input validation. Third, when a victim—such as a site administrator or another high-privileged user—views the affected area where the input is rendered, the web browser interprets the injected payload as legitimate executable script code rather than inert text data.\nThe payload executes within the security context of the victim's session, possessing access to Document Object Model (DOM) elements, session cookies, and local storage tokens. Depending on the privileges of the targeted user viewing the rendered payload, the post-exploitation impact can include the unauthorized execution of administrative actions, theft of session identifiers, or further pivoting within the web application. Network exposure involves standard HTTP/HTTPS request mechanisms utilized by the web application architecture, and authentication is strictly required at the Author privilege tier to successfully inject the initial payload."
}