External risk intelligence

Theme My Login WordPress Plugin Privilege Escalation Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-89079

The vulnerability affects a WordPress plugin designed to modify user login and account management functionality. Such plugins are typically installed on web-facing applications, making the associated account management endpoints accessible via the public internet as part of the standard deployment of a WordPress site.

Privilege Escalation

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability affects the Theme My Login plugin for WordPress, which could allow unauthenticated attackers to take over user accounts by changing passwords. The issue arises from improper validation of user identities before password updates, potentially impacting multi-site WordPress installations.

Unauthenticated attackers can change user passwords.
Affects WordPress account management and multi-site setups.
Confirm relevance and assess exposure to WordPress sites.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by targeting the Theme My Login plugin on WordPress multi-site installations. Since the plugin fails to adequately verify user identity before allowing password changes, an unauthenticated attacker can potentially take over any user account, leading to unauthorized access and control.

No authentication required to initiate attack.
Unauthenticated users can change arbitrary passwords.
Potential for account takeover and privilege escalation.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow unauthenticated attackers to change passwords for any user on multi-site WordPress installations when specific configurations are met, potentially leading to account takeover.

User account credentials.
Attacker changes passwords via exposed functionality.
Unauthorized access to user accounts.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Theme My Login plugin's privilege escalation vulnerability in WordPress necessitates action from teams managing WordPress instances, particularly those handling user account management and site security. The initial step involves identifying all WordPress sites utilizing this plugin, assessing their exposure to unauthenticated attackers (especially on multi-site setups), and pinpointing the specific application or platform owner responsible for each instance before planning remediation.

Identify WordPress instances and owners.
Verify unauthenticated access and multi-site setups.
Plan targeted remediation by owner.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Theme My Login plugin for WordPress?

Theme My Login is a plugin designed to customize and rebrand the standard WordPress login, registration, and password recovery screens. It replaces default WordPress user management pages with custom interfaces that match a site's theme, while also providing tools to manage user accounts and profiles directly from the frontend of a website.

What does CVE-2026-89079 mean for security?

This CVE describes a weakness classified as Improper Privilege Management (CWE-269). In plain English, the plugin fails to verify who is requesting a password change. Because it lacks a proper identity check, an attacker can bypass standard security barriers to reset any user's password, effectively gaining unauthorized control over accounts.

How can an attacker trigger this vulnerability?

An attacker targets the plugin's password update process. The vulnerability requires a specific multi-site configuration where the plugin fails to enforce authentication. Importantly, this bug does not trigger on standard, single-site WordPress installations, nor does it require the attacker to have an existing user account or any prior credentials to initiate the password change request.

Why is this CVE relevant to my website?

According to Halo Surface Signal, this vulnerability is highly relevant because the plugin modifies core account management endpoints that are typically exposed to the public internet. Since these WordPress sites are usually web-facing, the functionality used for this attack is readily accessible to anyone online, increasing the potential risk for site owners.

What should I do if I use Theme My Login?

First, conduct an inventory to identify which of your WordPress instances have the plugin installed, focusing specifically on multi-site environments. Once you have identified these sites, verify if they are using the affected versions and determine who owns each instance. Prioritize these sites for security updates and monitor them for unauthorized account activity while preparing for remediation.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.