CVE-2026-19991 stiofansisland CVE debrief

Who should care

Site administrators and security teams using the UsersWP plugin for WordPress should assess exposure and prioritize remediation. This vulnerability allows authenticated attackers with Subscriber-level access to delete arbitrary files on the server, which can lead to website compromise or data loss.

Why it matters

CVE-2026-19991 allows authenticated attackers to delete arbitrary files on WordPress servers using the UsersWP plugin. Site administrators should update the plugin and monitor for suspicious activity.

• Authenticated attackers with Subscriber-level access can delete arbitrary files on the server
• Deletion of critical files can lead to website compromise or data loss
• Requires verification of affected versions and remediation from official sources

Technical summary

The UsersWP plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient validation and normalization of user-supplied file paths in the upload_file_remove AJAX handler. The plugin stores the value of an account 'file' form field taken directly from $_POST when no real $_FILES upload is provided. At storage time the value is only checked with validate_file(), which passes any string that does not contain a literal '../'. When the value is later processed by upload_file_remove(), it is again gated with validate_file() and then normalized through uwp_get_file_relative_url(); that helper performs a global str_replace() of the uploads base URL against the stored URL, allowing a crafted URL to

Defensive priority

High

Recommended defensive actions

• Update the UsersWP plugin to a version that fixes the vulnerability
• Restrict access to the upload_file_remove AJAX handler
• Monitor server logs for suspicious file deletion activity
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability exists in versions up to and including 1.2.70 of the UsersWP plugin. An attacker can exploit this by providing a crafted file path that can be normalized to traverse directories, allowing deletion of arbitrary files.

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.