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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-4300

MEDIUM · 6.4 CVSS v3.1 Published 2026-04-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Robo Gallery plugin for WordPress is vulnerable to Stored XSS via the 'Loading Label' setting. The plugin uses a custom `|***...***|` marker pattern in its `fixJsFunction()` method to embed raw JavaScript within JSON configuration. While the Loading Label field (`rbs_gallery_LoadingWord`) is sanitized with `sanitize_text_field()`, this does not strip the marker pattern since it contains no HTML. Attackers with Author-level access can inject `|***alert(document.domain)***|` which passes sanitization, gets stored in post_meta, and when rendered, has the markers stripped resulting in arbitrary JavaScript execution in inline script tags.

MitigationThe `sanitize_text_field()` function should be updated to strip the `|***...***|` marker pattern, or the `fixJsFunction()` method should validate/filter the input before processing. Alternatively, the rendering logic should escape JavaScript output instead of blindly stripping markers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Robo Gallery plugin version
    Check the installed plugin version in WordPress under Plugins > Installed Plugins. Look for 'Robo Gallery' or 'robo-gallery' and note the version number.
    Affected if The installed version is 5.1.3 or lower (any version up to and including 5.1.3).
  2. Identify galleries using the plugin
    Search for posts or pages containing the [robo_gallery] shortcode, or look for gallery post types created by the plugin.
    Affected if Any gallery post or page using the Robo Gallery shortcode exists on the site.
  3. Inspect Loading Label setting for malicious markers
    Access the plugin settings for each gallery (usually via the gallery edit screen) and examine the 'Loading Label' field. Alternatively, query the post_meta table for meta_key values related to 'loading_label' or similar, looking for values containing the pattern |***...***|.
    Affected if Any gallery's Loading Label value contains the |***...***| marker pattern.
  4. Check rendered gallery output
    View the front-end of a page containing a Robo Gallery. View page source and search for the rendered Loading Label text. Look for JavaScript execution (such as alert(), document.domain, or similar) within inline script tags or event handlers.
    Affected if The rendered HTML contains unescaped JavaScript code derived from the Loading Label setting.

If the plugin version is 5.1.3 or lower AND any gallery exists with the |***...***| marker pattern in its Loading Label setting, the environment is affected by this stored XSS vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

The `sanitize_text_field()` function should be updated to strip the `|***...***|` marker pattern, or the `fixJsFunction()` method should validate/filter the input before processing. Alternatively, the rendering logic should escape JavaScript output instead of blindly stripping markers.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4300 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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