CVE-2026-42669: EventPrime Auth Bypass Vulnerability

CVE-2026-42669 Overview

CVE-2026-42669 is a Missing Authorization vulnerability [CWE-862] in the EventPrime WordPress plugin. The flaw stems from incorrectly configured access control security levels in the event calendar management plugin. Unauthenticated attackers can exploit broken access control to perform restricted actions over the network without user interaction. The vulnerability affects EventPrime versions through 4.3.2.0. According to the Patchstack advisory, attackers can compromise integrity by reaching functionality intended for authorized users only.

Critical Impact

Unauthenticated network attackers can bypass authorization checks in EventPrime, modifying restricted plugin data and undermining the integrity of WordPress sites running the plugin.

Affected Products

• EventPrime plugin for WordPress (eventprime-event-calendar-management)
• Versions from n/a through 4.3.2.0
• WordPress sites with the vulnerable EventPrime plugin installed and active

Discovery Timeline

• 2026-06-02 - CVE-2026-42669 published to NVD
• 2026-06-02 - Last updated in NVD database

Technical Details for CVE-2026-42669

Vulnerability Analysis

The vulnerability is a Broken Access Control issue in the EventPrime WordPress plugin. EventPrime exposes plugin actions without verifying that the requesting user holds the required capability or role. An unauthenticated remote attacker can issue crafted HTTP requests to reach restricted plugin endpoints. The Patchstack report classifies the impact as integrity-affecting, meaning attackers can modify or trigger plugin functionality reserved for privileged users. Confidentiality and availability are not directly impacted according to the CVSS vector. The EPSS data indicates a low current probability of observed exploitation, but the unauthenticated network reachability keeps the issue notable for site operators.

Root Cause

The root cause is missing authorization enforcement in plugin request handlers [CWE-862]. EventPrime relies on incorrectly configured access control checks that do not validate the caller's privilege level before performing sensitive actions. Standard WordPress patterns such as current_user_can() checks or nonce validation appear to be absent or improperly applied on the affected handlers, allowing requests from any source to succeed.

Attack Vector

The attack vector is Network with low complexity and no privileges or user interaction required. An attacker sends crafted HTTP requests to the WordPress site hosting the EventPrime plugin. Because authorization is not enforced, the plugin processes the request and performs the restricted action. Refer to the Patchstack Vulnerability Report for further technical context. No public proof-of-concept code is currently available.

Detection Methods for CVE-2026-42669

Indicators of Compromise

• Unexpected modification of EventPrime event entries, bookings, or plugin configuration without corresponding administrator activity in WordPress audit logs.
• HTTP POST or GET requests to EventPrime AJAX or REST endpoints originating from unauthenticated sessions or anonymous IP addresses.
• New or altered events created outside of normal business workflows on sites running EventPrime 4.3.2.0 or earlier.

Detection Strategies

• Inventory all WordPress installations and identify sites running the EventPrime plugin at version 4.3.2.0 or earlier.
• Review web server access logs for repeated requests targeting EventPrime endpoints under paths such as /wp-admin/admin-ajax.php and EventPrime REST routes.
• Correlate plugin database changes with authenticated administrator sessions to surface unauthorized modifications.

Monitoring Recommendations

• Enable WordPress audit logging to capture plugin setting changes, event creation, and option modifications.
• Deploy a Web Application Firewall (WAF) ruleset that flags anonymous requests to EventPrime action handlers.
• Forward WordPress and web server logs to a centralized analytics platform for behavioral baseline analysis and anomaly identification.

How to Mitigate CVE-2026-42669

Immediate Actions Required

• Update EventPrime to a version later than 4.3.2.0 as soon as the vendor publishes a fixed release.
• Restrict access to the WordPress admin and AJAX endpoints using IP allowlisting where feasible.
• Audit the plugin's event data and configuration for unauthorized changes introduced before patching.

Patch Information

At the time of publication, the Patchstack advisory lists the vulnerable range as n/a through 4.3.2.0. Site operators should consult the Patchstack Vulnerability Report and the EventPrime plugin page on WordPress.org for the fixed version once released, then upgrade through the WordPress plugin manager.

Workarounds

• Temporarily deactivate the EventPrime plugin if patching is not yet possible and the calendar functionality is not business-critical.
• Apply WAF rules that block unauthenticated requests to EventPrime action handlers and REST routes.
• Limit external exposure of the WordPress admin surface using HTTP authentication or network-level controls.

# Configuration example: WAF rule to block unauthenticated EventPrime AJAX actions
# (adapt the action parameter list to your environment)
SecRule REQUEST_URI "@contains /wp-admin/admin-ajax.php" \
    "chain,deny,status:403,id:1042669,msg:'Block unauthenticated EventPrime action'"
    SecRule ARGS:action "@rx ^(ep_|eventprime_)" \
        "chain"
        SecRule &REQUEST_COOKIES:/wordpress_logged_in_/ "@eq 0"