CVE-2026-17559: Content Protector (Passster) < 4.3.9 - Unauthenticated Protected Content Disclosure via REST Path Allowlist Bypass
The Passster WordPress plugin before 4.3.9 does not correctly match its own public endpoint paths when deciding which REST API requests may bypass global password protection, comparing them as an unanchored substring of the request URI rather than against the resolved route, allowing an unauthenticated attacker to read the content of globally password-protected posts and pages.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Passster (Content Protector) WordPress pluginto a version that resolves this vulnerability.Fixed in 4.3.9
Event History
Frequently Asked Questions
Which sites are exposed?
Sites using Passster versions earlier than 4.3.9 are exposed if they rely on the plugin's global password protection for posts or pages. The issue affects content protected through that global mechanism.
Does exploitation require an account or user interaction?
No. An attacker can exploit the issue without authentication or user interaction by making a REST API request whose URI triggers the plugin's incorrect public-endpoint path matching.
How can I determine whether my site is affected?
Check the installed Passster version and whether global password protection is enabled for content. Versions before 4.3.9 with globally protected posts or pages should be treated as affected.