CVE-2026-107756: Meow Lightbox <= 5.6.2 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Output Buffering parser noise substitution via comment body + display_name
The Meow Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'displayname + comment' parameter in all versions up to, and including, 5.6.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability is only exploitable when the plugin's Output Buffering option is enabled (disabled by default), and requires the attacker to have at least one previously approved comment on the site so that subsequent comments are auto-approved by WordPress core.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable the plugin's Output Buffering option, which is enabled for exploitation and disabled by default.
Meow Lightbox Output Buffering = disabled
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker must be authenticated with at least Subscriber-level access. They must also have at least one previously approved comment, because WordPress must auto-approve their subsequent malicious comment.
Are default plugin installations affected?
No. Exploitation requires Meow Lightbox's Output Buffering option to be enabled, and that option is disabled by default.
What conditions trigger the malicious script?
The attacker injects script through the display name and comment content. The stored script executes when a user accesses a page containing the injected content.
What can be done before updating?
Disable the Output Buffering option in Meow Lightbox. Also review comments from authenticated users, particularly accounts with previously approved comments, for suspicious display names or comment bodies.