CVE-2026-0551 buildwps CVE debrief

Who should care

Defenders responsible for WordPress installations with the PPWP – Password Protect Pages plugin should assess the vulnerability and potential impact on their systems, focusing on verifying the presence of other plugins or themes that could provide a POP chain, and applying updates if available. Security teams and vulnerability management teams should prioritize verifying affected scope, assessing potential impact, and planning vendor-supported updates or

Why it matters

CVE-2026-0551 allows authenticated attackers to inject PHP Objects, potentially leading to code execution or data retrieval if a POP chain is present in another plugin or theme.

• Verification of other plugins or themes for POP chain presence
• Potential for code execution or sensitive data retrieval if a POP chain is present
• Need for updates or mitigations for the PPWP – Password Protect Pages plugin
• Monitoring for suspicious activity related to PHP Object Injection

Technical summary

The PPWP – Password Protect Pages plugin for WordPress is vulnerable to PHP Object Injection due to deserialization of untrusted input from the 'post_protection_roles' parameter. This allows authenticated attackers with Contributor-level access and above to inject a PHP Object. However, the impact is limited without another plugin or theme containing a POP chain. The vulnerability can be exploited if a POP chain is present via an additional plugin or theme installed on the target system, potentially allowing attackers to perform actions like delete arbitrary files, retrieve sensitive data, or execute code

Defensive priority

Defenders should prioritize verifying the presence of other plugins or themes that could provide a POP chain, assessing the potential impact, and applying updates if available.

Recommended defensive actions

• Verify the presence of other plugins or themes that could provide a POP chain
• Assess the potential impact of the vulnerability on the system
• Apply updates if available for the PPWP – Password Protect Pages plugin
• Monitor for suspicious activity related to PHP Object Injection
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability was reported by [email protected] and is documented in the CVE Program record and NVD vulnerability detail pages. The PPWP – Password Protect Pages plugin for WordPress is vulnerable to PHP Object Injection due to deserialization of untrusted input from the 'post_protection_roles' parameter. This allows authenticated attackers with Contributor-level access and above to inject a PHP Object. However, the impact is limited without another plugin or theme containing a POP chain. Evidence is limited to CVE Program, N

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.