CVE-2025-12520: 
WordPress vulnerability analysis and mitigation

The WP Airbnb Review Slider WordPress plugin (versions up to 4.2) contains a Stored Cross-Site Scripting vulnerability (CVE-2025-12520) discovered in November 2025. The vulnerability exists in the admin settings due to insufficient URL validation that allows users to pull in malicious HTML files. This security issue affects multi-site installations and installations where unfiltered_html has been disabled (NVD CVE).

The vulnerability stems from insufficient URL validation in the plugin's functionality that fetches and stores HTML content. The issue combines Server-Side Request Forgery (SSRF) with Stored XSS, where attacker-controlled HTTP responses can be fetched and stored by the plugin. The vulnerability has been assigned a CVSS v3.1 score of 4.0 (Medium) with the vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:N, indicating network accessibility but requiring high privileges and user interaction (Cyber Research Hub, NVD CVE).

The vulnerability allows authenticated attackers with administrator-level permissions to inject arbitrary web scripts into pages. When exploited, these malicious scripts execute whenever a user accesses an affected page. The impact is particularly significant for multi-site installations and systems where unfiltered_html has been disabled (NVD CVE, Cyber Research Hub).

The vulnerability has been patched in version 4.3 of the WP Airbnb Review Slider plugin. The fix includes enhanced security measures such as destination verification restricting outbound fetches to validated Airbnb domains, safer persistence methods preventing direct writing to web-executable plugin files, and improved content sanitization for remote sources (WordPress Plugin).