CVE-2026-54869 in IMPress for IDX Broker Plugin
Summary
by MITRE • 10/13/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in IDX Broker IMPress for IDX Broker idx-broker-platinum allows Stored XSS.This issue affects IMPress for IDX Broker: from n/a through 3.3.1.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/13/2026
The identified security flaw represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this vulnerability manifests as a Stored XSS within the IMPress for IDX Broker plugin, affecting versions ranging from n/a through 3.3.1. Unlike reflected XSS attacks where malicious scripts are embedded in URLs and executed only when a user clicks a specific link, stored vulnerabilities persist on the target server. In this context, an attacker can inject malicious JavaScript code into data fields that are subsequently saved to the backend database or persistent storage mechanisms of the IDX Broker platform. When other users visit pages containing this tainted data, their browsers render the content and execute the embedded script automatically without any further interaction from the victim. This persistence makes stored XSS particularly dangerous as it affects every user who views the compromised page, significantly expanding the potential blast radius of the attack compared to transient vulnerabilities.
From a technical perspective, the root cause lies in insufficient input validation and output encoding within the plugin's codebase. The application fails to properly sanitize special characters such as angle brackets, quotes, and ampersands before storing user-supplied data. Furthermore, it does not adequately encode this data when rendering it back into HTML contexts. This lack of defense-in-depth allows an attacker to break out of the expected data context and inject executable script tags or event handlers like onerror or onload. The vulnerability likely exists in areas where users can submit content for display, such as property descriptions, comments, profile information, or other user-generated fields within the IDX Broker interface. Because the malicious payload is stored server-side, it remains active until manually removed by an administrator, creating a long-term security risk that persists even after the initial attack vector has been addressed if not properly patched.
The operational impact of this vulnerability is severe and multifaceted. The primary consequence is the compromise of user confidentiality and integrity through session hijacking. An attacker can steal authentication cookies or tokens associated with active sessions, allowing them to impersonate legitimate users, including potentially high-privilege administrators. This access enables unauthorized modification of property listings, deletion of data, or insertion of phishing links that trick other agents into revealing their credentials. Additionally, the vulnerability facilitates drive-by attacks where the injected script can exploit browser vulnerabilities to install malware on victims' devices. It also supports clickjacking and defacement scenarios, damaging the reputation of real estate professionals who rely on IDX Broker for their online presence. The ability to execute arbitrary JavaScript means an attacker has full control over the DOM in the context of the victim's session, potentially bypassing same-origin policy restrictions to access sensitive data from other tabs or applications running within the same browser environment.
This vulnerability aligns with CWE-79, which defines Improper Neutralization of Input During Web Page Generation: Cross-site Scripting. It is also mapped to MITRE ATT&CK technique T1059.007, specifically JavaScript execution via web browsers, and often serves as a precursor to data exfiltration techniques such as T1005 or credential theft methods like T1539. The persistence of the attack vector classifies it under persistent threats where initial access leads to long-term compromise if not remediated promptly. Security professionals should note that stored XSS is frequently exploited in conjunction with social engineering, as attackers may craft payloads designed to look like legitimate property updates or messages to increase the likelihood of victim interaction and data exposure.
Mitigation strategies must focus on both immediate patching and long-term secure coding practices. The most effective remediation is to upgrade IMPress for IDX Broker to a version greater than 3.3.1, where the developers have presumably implemented proper input sanitization and output encoding mechanisms. For organizations unable to immediately update due to compatibility concerns, implementing Web Application Firewall rules can provide temporary protection by detecting and blocking common XSS payloads in HTTP requests. However, this is not a substitute for patching. Developers should enforce strict allow-list validation on all user inputs and utilize context-aware output encoding libraries that automatically escape special characters based on the rendering context, whether it be HTML body, attribute, JavaScript, or CSS. Additionally, implementing Content Security Policy headers can mitigate the impact of successful XSS attacks by restricting the sources from which scripts are allowed to load, thereby preventing the execution of injected inline scripts even if they bypass input filters. Regular security audits and static code analysis tools should also be employed to identify similar vulnerabilities across other plugins in the WordPress ecosystem.