Description

Contributor Cross Site Scripting (XSS) in Magazine Blocks <= 1.8.6 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-24T12:16:55.960Z",
  "pubdate": "2026-08-24T12:16:55.960Z",
  "executiveSummary": "A Cross-Site Scripting (XSS) vulnerability exists in the Magazine Blocks product within versions 1.8.6 and below. This security flaw allows a contributor-level user to inject arbitrary malicious scripts, such as JavaScript, into web pages rendered by the application.\nThe vulnerability directly impacts the integrity and confidentiality of the affected systems by exposing authenticated users, including higher-privileged administrators, to session hijacking, defacement, and unauthorized actions performed within the context of their session.\nThe risk implication is moderate to high, depending on the privileges of the victim interacting with the malicious payload. The attacker is required to possess contributor-level authentication capabilities on the target WordPress installation to successfully orchestrate the exploitation vector.\nNo complex social engineering is strictly required beyond the placement of the payload within block parameters or attributes processed by the vulnerable component. Remediation requires updating the affected software to a patched version once available or restricting untrusted user roles from publishing vulnerable block types.",
  "technicalDetails": "The vulnerability stems from improper input sanitization and inadequate output encoding within the Magazine Blocks plugin or theme components. Specifically, user-supplied data provided via specific block attributes or parameters handled by contributor-level accounts is insufficiently sanitized before being stored in the database and subsequently reflected or rendered in the Document Object Model (DOM).\nThe affected component handles block rendering logic where input data lacks contextual output escaping, allowing raw HTML and JavaScript vectors to be injected. The affected versions include all releases of Magazine Blocks up to and including version 1.8.6.\nExploitation requires authenticated access with at least a contributor-level role, meaning an attacker must first authenticate to the target application. Network exposure is standard HTTP/HTTPS access to the administrative or post-editing interface where blocks are created and manipulated.\nThe attack flow proceeds as follows: First, the authenticated attacker with contributor privileges crafts a malicious payload containing executable JavaScript encapsulated within block attributes or properties. Second, the attacker saves or publishes a post containing the engineered block. The application accepts the unvalidated input and writes it directly to the backend database without proper neutralization. Third, when an unsuspecting user—potentially an administrator with elevated privileges—views the rendered post or administrative preview interface, the server outputs the stored payload directly into the response without contextual HTML encoding.\nThe browser of the victim parses the injected payload as executable script within the security context of the origin site. The payload executes arbitrary actions such as stealing session cookies, performing unauthorized API requests, or creating new administrative accounts depending on the permissions of the victim viewing the compromised content."
}