PPWP permits Contributor-level PHP object injection

PPWP through 1.9.18 deserializes untrusted data from the post_protection_roles parameter. A Contributor or higher can inject a PHP object; PPWP does not itself contain a known POP chain, so further impact requires another installed plugin or theme with a usable chain. Depending on that chain, exploitation could disclose data, delete files or execute code.

CVE / CNA score 8.8 CVSS 3.1 · security@wordfence.com

NVD score Pending NVD has not published its own CVSS assessment.

Component: PPWP – Password Protect Pages
Plugin slug: password-protect-page
Affected: <= 1.9.18
Safe version: See mitigation notes
Published: Aug 23, 2026
Weakness: CWE-502 — Deserialization of Untrusted Data

This CVE was published Aug 23, 2026 and is one of 7 known issues for this plugin.

What to do

Update, patch or deactivate.

No fixed release is identified for CVE-2026-0551. Update PPWP when a release after 1.9.18 is confirmed to fix this issue; until then, restrict Contributor access or deactivate the plugin when warranted and review installed extensions for deserialization gadget exposure.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The PPWP – Password Protect Pages plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.9.18 via deserialization of untrusted input from the 'post_protection_roles' vulnerable parameter. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Primary and upstream sources

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