Flipbox <= 3.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'flip-box-image-upload-url-01-alt' Parameter
Strategic Overview
- Status
- Patched in 3.1.2
- Affected Plugin
- Flipbox – Awesomes Flip Boxes Image Overlay
- Affected Version
<= 3.1.1- CVSS
- 6.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation
- CVE
CVE-2026-109973
At a glance
CVE-2026-109973 is a medium-severity Improper Neutralization of Input During Web Page Generation vulnerability in the Flipbox WordPress plugin, affecting versions <= 3.1.1. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 3.1.2; sites on affected versions should update now. Disclosed November 2026, reported by Wordfence PRISM.
Vulnerability Overview
The Image Hover Effects Ultimate Visual Composer (Flipbox - Awesomes Flip Boxes Image Overlay) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'flip-box-image-upload-url-01-alt' parameter in versions up to, and including, 3.1.1. This is due to the plugin saving the image-alt field through sanitize_text_field() in Inc/Style22::register_child() (and Inc/Style18, 19, 20, 25, 29) — which preserves the double-quote character — and then concatenating the stored value into a double-quoted HTML attribute in Public_Render/Style22::default_render() (and the corresponding Style18/19/20/25/29 renderers) with no esc_attr() escaping. This makes it possible for authenticated attackers, with contributor-level access and above (when an administrator has delegated the plugin's 'Who can edit' capability via the plugin Settings page, or on multisite installations where even administrators lack unfiltered_html), to inject arbitrary web scripts in pages that will execute whenever a user accesses any page containing an affected [oxilab_flip_box] shortcode or block.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation
Flipbox <= 3.1.1 carries this weakness at flip-box-image-upload-url-01-alt, and reaching it takes an account at Contributor level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Flipbox the fix is 3.1.2: builds <= 3.1.1 are affected, anything from 3.1.2 onward is not.
Remediation
Update to version 3.1.2, or a newer patched version
How does WordSec protect against this?
An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Flipbox 3.1.2 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in Flipbox – Awesomes Flip Boxes Image Overlay
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C