CVE-2026-82519: Really Simple Security 2FA Bypass Vulnerability

CVE-2026-82519 Overview

CVE-2026-82519 is a missing authorization vulnerability [CWE-862] in the Really Simple Security plugin for WordPress before version 9.8.2. The flaw resides in the profile-page update handler, which fails to enforce authorization checks on a specific code path. Authenticated low-privileged attackers can submit a crafted POST request that omits the two-factor-authentication field. This bypass skips nonce verification and triggers delete_two_fa_meta(), which resets the grace period anchor timestamp. As a result, mandatory two-factor authentication (2FA) enforcement is deferred indefinitely on each login cycle.

Critical Impact

Authenticated attackers can indefinitely bypass mandatory two-factor authentication enforcement, weakening account security for affected WordPress sites.

Affected Products

• Really Simple Security plugin for WordPress versions prior to 9.8.2
• WordPress installations using Really Simple Security with 2FA enforcement enabled
• Sites relying on the plugin's grace period mechanism for mandatory 2FA rollout

Discovery Timeline

• 2026-09-14 - CVE-2026-82519 published to NVD
• 2026-09-14 - Last updated in NVD database

Technical Details for CVE-2026-82519

Vulnerability Analysis

The vulnerability exists in the Really Simple Security plugin's profile-page update handler. The handler contains an unguarded code path that processes profile updates without verifying authorization or nonce values when the two-factor-authentication field is absent from the POST payload. This design flaw allows any authenticated user, including low-privileged subscriber accounts, to invoke sensitive functionality intended to be gated by administrative controls.

When the crafted request reaches the handler, execution flows to delete_two_fa_meta(). This function clears the user's 2FA metadata, including the grace period anchor timestamp used to enforce mandatory two-factor authentication after a configurable window. Because the anchor resets on every login cycle, the enforcement deadline never elapses.

The impact is a persistent bypass of mandatory 2FA policies. Sites that depend on Really Simple Security to enforce 2FA lose that assurance for any user who exploits the flaw, weakening defense against credential-based attacks.

Root Cause

The root cause is a missing authorization check [CWE-862] on a branch of the profile update handler. The code path executes without validating the user's capability or verifying the request nonce, allowing state-changing calls to delete_two_fa_meta() from unauthorized contexts.

Attack Vector

Exploitation requires network access to the WordPress site and valid low-privileged credentials. The attacker submits a POST request to the profile update endpoint without the two-factor-authentication form field. The handler skips nonce and capability verification and invokes the metadata deletion routine.

The vulnerability is described in prose only; no verified public exploit code is available. See the VulnCheck Security Advisory for the disclosed technical details.

Detection Methods for CVE-2026-82519

Indicators of Compromise

• POST requests to the WordPress profile update endpoint from low-privileged users that omit the two-factor-authentication parameter.
• Unexpected deletion or reset of 2FA-related user metadata associated with the Really Simple Security plugin.
• Repeated resets of the 2FA grace period anchor timestamp across login cycles for the same user account.

Detection Strategies

• Audit WordPress user meta tables for missing or repeatedly cleared Really Simple Security 2FA metadata entries.
• Review web server access logs for anomalous profile update POST requests lacking expected 2FA fields.
• Correlate authentication events with 2FA metadata state changes to identify accounts that should be enforcing 2FA but are not.

Monitoring Recommendations

• Enable WordPress audit logging to capture profile update events and user meta modifications.
• Alert on any invocation of delete_two_fa_meta() or equivalent metadata reset operations outside expected administrative workflows.
• Track the population of enforced-2FA users over time and investigate unexpected drops in enrollment.

How to Mitigate CVE-2026-82519

Immediate Actions Required

• Upgrade the Really Simple Security plugin to version 9.8.2 or later on all WordPress sites.
• Audit existing user accounts to confirm 2FA enforcement status and re-enroll any accounts with cleared 2FA metadata.
• Rotate credentials for low-privileged accounts that show evidence of exploitation attempts.

Patch Information

The vendor has addressed the vulnerability in Really Simple Security version 9.8.2. Administrators should install the update through the WordPress plugin management interface or via WP-CLI. See the WordPress Plugin Documentation for release information and the VulnCheck Security Advisory for the disclosed fix scope.

Workarounds

• Restrict access to the WordPress admin and profile endpoints using web application firewall rules until the plugin is updated.
• Temporarily disable the Really Simple Security 2FA enforcement feature and rely on an alternative 2FA plugin if patching is delayed.
• Limit low-privileged account creation and monitor existing subscriber accounts closely during the remediation window.

# Update the Really Simple Security plugin via WP-CLI
wp plugin update really-simple-ssl --version=9.8.2
wp plugin list --name=really-simple-ssl --fields=name,status,version