CVE-2026-16603

Content Protector (Passster) <= 4.3.5 - Unauthenticated Category-Locked Content Disclosure

2026-07-27 00:00
Revanth Hari Narayana Matte

Strategic Overview

Status
Patched in 4.3.6
Affected Plugin
Passster – Password Protect Pages and Content
Affected Version
<= 4.3.5
CVSS
5.3Medium
Weakness type
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor
CVE
CVE-2026-16603
View all Passster – Password Protect Pages and Content vulnerabilities

At a glance

CVE-2026-16603 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor vulnerability in the Passster WordPress plugin, affecting versions <= 4.3.5. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.3.6; sites on affected versions should update now. Disclosed July 2026, reported by Revanth Hari Narayana Matte.

Vulnerability Overview

The Content Protector (Passster) plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 4.3.5. This is due to missing filtering of rendered content and excerpt fields for category-locked posts in the REST API response, allowing the core REST API to bypass the category-lock protection entirely. This makes it possible for unauthenticated attackers to access category-locked post content in plaintext via the WordPress core REST API without providing a valid password.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

Reaching this weakness in Passster <= 4.3.5 takes no account at all. Sensitive information exposure means data the application intended to keep internal is returned to a caller who should not be able to see it.

The disclosed data — credentials, tokens, customer records or internal paths — is usually worth more as material for a follow-up attack than as an end in itself. For Passster the fix is 4.3.6: builds <= 4.3.5 are affected, anything from 4.3.6 onward is not.

Remediation

Update to version 4.3.6, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: Passster 4.3.6 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-16603https://www.wordfence.com/threat-intel/vulnerabilities/id/fbd74378-ce7b-4438-81d4-fc164005a832https://nvd.nist.gov/vuln/detail/CVE-2026-16603

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C