CVE-2026-7523: Alba Board WordPress Auth Bypass Flaw

CVE-2026-7523 Overview

CVE-2026-7523 is an authorization bypass vulnerability in the Alba Board plugin for WordPress affecting all versions up to and including 2.1.3. The plugin fails to verify that requesting users are authorized to access private alba_card post data. Authenticated attackers with subscriber-level access can read arbitrary private card data including titles, descriptions, assignees, due dates, tags, and comments intended for Administrators and Editors. The handler is registered via the wp_ajax_nopriv_ hook, and its nonce is exposed to all visitors through wp_localize_script on pages containing the [alba_board] shortcode. Unauthenticated users who can reach any such page can therefore exploit the flaw. The weakness is categorized as Missing Authorization [CWE-862].

Critical Impact

Unauthenticated and low-privilege users can read private project board card data containing potentially sensitive assignments, comments, and internal task descriptions.

Affected Products

• Alba Board plugin for WordPress — all versions up to and including 2.1.3
• WordPress sites rendering the [alba_board] shortcode on any public-facing page
• Deployments using the vulnerable ajax-card-details.php handler

Discovery Timeline

• 2026-06-05 - CVE-2026-7523 published to NVD
• 2026-06-08 - Last updated in NVD database

Technical Details for CVE-2026-7523

Vulnerability Analysis

The vulnerability resides in the ajax-card-details.php handler shipped with the Alba Board plugin. The handler responds to AJAX requests for the contents of alba_card custom post type entries, which represent individual cards on a project board. According to the Wordfence Vulnerability Analysis, the handler does not validate whether the requesting user possesses the capability required to view a given card. The plugin registers the endpoint using WordPress's wp_ajax_nopriv_ hook, which exposes the action to unauthenticated visitors. A nonce required by the endpoint is emitted to the browser by wp_localize_script on every page that renders the [alba_board] shortcode. Any visitor who can load such a page obtains a valid nonce and can submit requests for arbitrary card IDs. Although the CVSS vector reports the privileges-required component as Low, the public exposure of the nonce effectively allows unauthenticated exploitation against sites that publish the shortcode publicly.

Root Cause

The root cause is missing authorization logic [CWE-862] in the AJAX card-details handler. The function retrieves the requested alba_card post and returns its fields without calling current_user_can() or otherwise verifying that the caller has rights to view the post. Nonce validation alone is treated as sufficient, which conflates request integrity with access control.

Attack Vector

An attacker loads any front-end page that renders the [alba_board] shortcode and extracts the AJAX nonce localized into JavaScript. The attacker then issues POST requests to admin-ajax.php with the relevant action and a target alba_card post ID. The server returns the full card payload regardless of the card's intended audience. Iterating over post IDs allows enumeration of every private card on the site. See the WordPress Plugin Code Detail for the affected source.

Detection Methods for CVE-2026-7523

Indicators of Compromise

• Repeated POST requests to wp-admin/admin-ajax.php targeting the Alba Board card-details action from a single source IP
• Sequential or enumerative post_id parameters in AJAX request bodies indicating ID brute-forcing
• Requests originating from sessions without authenticated WordPress cookies hitting the wp_ajax_nopriv_ endpoint

Detection Strategies

• Review WordPress access logs for high-volume access to admin-ajax.php correlated with requests for the [alba_board] shortcode pages
• Deploy web application firewall rules to flag anonymous requests to the Alba Board card-details action across multiple post IDs
• Audit installed plugin versions and flag any Alba Board installation at or below 2.1.3

Monitoring Recommendations

• Forward WordPress and reverse-proxy access logs to a centralized analytics platform for ongoing review
• Alert on unauthenticated AJAX requests that return non-empty card payloads to identify successful data retrieval
• Track plugin inventory across WordPress fleets and monitor advisories from the Wordfence Vulnerability Analysis

How to Mitigate CVE-2026-7523

Immediate Actions Required

• Update the Alba Board plugin to a version later than 2.1.3 once available, or deactivate the plugin if no patched release exists
• Remove the [alba_board] shortcode from publicly accessible pages to prevent nonce exposure to anonymous visitors
• Restrict access to pages rendering the shortcode using authentication and role-based controls

Patch Information

Review the upstream change in the WordPress ChangeSet and apply the latest plugin release from the WordPress plugin repository. Verify post-update that the AJAX handler enforces current_user_can() checks against the requested alba_card post.

Workarounds

• Block unauthenticated requests to admin-ajax.php for the Alba Board card-details action at the WAF or reverse proxy layer
• Move pages containing the [alba_board] shortcode behind authentication to prevent nonce harvesting
• Audit existing alba_card posts and remove or relocate any sensitive content until the plugin is patched

# Example: block anonymous POSTs to the vulnerable AJAX action at the nginx layer
location = /wp-admin/admin-ajax.php {
    if ($http_cookie !~* "wordpress_logged_in") {
        set $block_ajax 1;
    }
    if ($request_body ~* "action=alba_card_details") {
        set $block_ajax "${block_ajax}1";
    }
    if ($block_ajax = "11") {
        return 403;
    }
}