CVE-2026-17559 Content Protector (Passster) < 4.3.9 - Unauthenticated Protected Content Disclosure via REST Path Allowlist Bypass
Unauthenticated attackers can bypass password protection to read protected content due to flawed REST API path matching in the Passster plugin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-17559?
CVE-2026-17559 is a medium-severity missing authorization vulnerability in Unknown Passster, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-17559?
How do I fix CVE-2026-17559?
No fix has been published for CVE-2026-17559 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-17559 being exploited?
There is no known exploitation of CVE-2026-17559 in the wild and no public exploit code.
Sources
Also known as GHSA-w4ph-xfmv-g57q.