CVE-2026-4300

Robo Gallery <= 5.1.3 - Authenticated (Author+) Stored Cross-Site Scripting via 'Loading Label' Setting

Strategic Overview

Status
Patched in 5.1.4
Affected Version
<= 5.1.3
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-4300
View all Robo Gallery – Photo & Image Slider vulnerabilities

At a glance

CVE-2026-4300 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Robo Gallery WordPress plugin, affecting versions <= 5.1.3. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Author level or above. The issue is fixed in version 5.1.4; sites on affected versions should update now. Disclosed April 2026, reported by Athiwat Tiprasaharn (Jitlada).

Vulnerability Overview

The Robo Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Loading Label' setting in all versions up to, and including, 5.1.3. The plugin uses a custom `|***...***|` marker pattern in its `fixJsFunction()` method to embed raw JavaScript function references within JSON-encoded configuration objects. When a gallery's options are rendered on the frontend, `json_encode()` wraps all string values in double quotes. The `fixJsFunction()` method then strips the `"|***` and `***|"` sequences, effectively converting a JSON string value into raw JavaScript code. The Loading Label field (stored as `rbs_gallery_LoadingWord` post_meta) is an `rbstext` type field that is sanitized with `sanitize_text_field()` on save. While this strips HTML tags, it does not strip the `|***...***|` markers since they contain no HTML. When a user inputs `|***alert(document.domain)***|`, the value passes through sanitization intact, is stored in post_meta, and is later retrieved and output within an inline `<script>` tag via `renderMainBlock()` with the quote markers stripped — resulting in arbitrary JavaScript execution. The gallery post type uses `capability_type => 'post'`, allowing Author-level users to create galleries. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page containing the gallery shortcode.

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 ('Cross-site Scripting')

Robo Gallery <= 5.1.3 carries this weakness at post, and reaching it takes an account at Author 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 Robo Gallery the fix is 5.1.4: builds <= 5.1.3 are affected, anything from 5.1.4 onward is not.

Remediation

Update to version 5.1.4, or a newer patched version

How does WordSec protect against this?

An attacker needs Author 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: Robo Gallery 5.1.4 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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