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PatchSiren cyber security CVE debrief

CVE-2026-19116 User Frontend CVE debrief

The User Frontend WordPress plugin before 4.3.11 does not prevent user-supplied field values from being deserialized when a submitted post is reopened in its frontend editing form, allowing authenticated users with subscriber-level access and above to perform PHP Object Injection, which may lead to remote code execution when a suitable gadget chain is present on the site.

Vendor
User Frontend
Product
User Frontend
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-02
Original CVE updated
2026-09-03
Advisory published
2026-09-02
Advisory updated
2026-09-03

Who should care

Administrators and security teams responsible for WordPress installations, particularly those using the User Frontend plugin, should be aware of this vulnerability. Ensuring the plugin is updated to version 4.3.11 or later is crucial to mitigate the risk of PHP Object Injection and potential remote code execution.

Technical summary

The User Frontend WordPress plugin before 4.3.11 is vulnerable to PHP Object Injection due to improper handling of user-supplied field values during post reopening in the frontend editing form. Authenticated users with subscriber-level access and above can exploit this to potentially achieve remote code execution if a suitable gadget chain is present on the site. The vulnerability has been assigned a CVSS score of 8.8, indicating high severity.

Defensive priority

Authenticated users with subscriber-level access and above may be able to perform PHP Object Injection, potentially leading to remote code execution.

Recommended defensive actions

  • Inventory and verify installed WordPress plugins, especially User Frontend, to ensure version 4.3.11 or later is deployed.
  • Restrict access to sensitive areas of the WordPress site, particularly the frontend editing form.
  • Implement monitoring to detect potential PHP Object Injection attempts.
  • Consider compensating controls such as Web Application Firewalls (WAFs) to detect and prevent attacks.
  • Review and update incident response plans to address potential remote code execution scenarios.

Evidence notes

The CVE record and NVD entry provide details about the vulnerability in the User Frontend WordPress plugin. The plugin does not prevent user-supplied field values from being deserialized, allowing for PHP Object Injection. The vulnerability has a CVSS score of 8.8 and is considered HIGH severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-19116 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-19116

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-19116 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-19116

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.