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

CVE-2026-2021

MEDIUM · 6.4 CVSS v3.1 Published 2026-06-18
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 Slideshow Gallery LITE plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'alwaysauto' shortcode attribute in all versions up to, and including, 1.8.5. This is due to insufficient input sanitization and output escaping on user-supplied attributes. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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 Slideshow Gallery LITE WordPress plugin versions up to 1.8.5 fails to sanitize and escape the 'alwaysauto' shortcode attribute, allowing authenticated users with Contributor-level access or higher to inject malicious JavaScript. This stored XSS executes whenever a user views a page containing the crafted shortcode.

MitigationUpdate to the latest version of the Slideshow Gallery LITE plugin or implement proper input sanitization using WordPress sanitization functions (such as sanitize_text_field) and output escaping (such as esc_attr) on the 'alwaysauto' attribute before rendering.

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. Confirm Slideshow Gallery LITE plugin is installed
    Navigate to WordPress admin dashboard > Plugins and look for 'Slideshow Gallery LITE' in the installed plugins list, or check the /wp-content/plugins/slideshow-gallery directory exists on the server
    Affected if Plugin is not installed or not present in the filesystem
  2. Identify the installed plugin version
    In WordPress admin > Plugins, click on the plugin name to view details, or inspect the main plugin file (slideshow-gallery.php) and look for the 'Version' header comment
    Affected if Version is 1.8.5 or lower (any version up to and including 1.8.5)
  3. Check for shortcode usage in content
    Search the WordPress database (wp_posts table) or use a plugin to search for occurrences of the shortcode [slideshow_gallery] in posts, pages, or widgets, particularly looking for the 'alwaysauto' attribute
    Affected if The [slideshow_gallery] shortcode with 'alwaysauto' attribute is present in any published content
  4. Inspect how the alwaysauto attribute is processed
    Examine the plugin source file that handles the shortcode (typically slideshow-gallery.php or a related shortcode handler file) and locate the code that outputs the 'alwaysauto' attribute value without escaping
    Affected if The code outputs the alwaysauto value using echo or print without esc_attr, esc_html, or similar escaping functions

The environment is affected if the Slideshow Gallery LITE plugin version 1.8.5 or lower is installed AND the vulnerable shortcode with the alwaysauto attribute exists in published content.

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

Update to the latest version of the Slideshow Gallery LITE plugin or implement proper input sanitization using WordPress sanitization functions (such as sanitize_text_field) and output escaping (such as esc_attr) on the 'alwaysauto' attribute before rendering.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-2021 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2026-2021 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data