CVE-2026-48873 Overview
CVE-2026-48873 is an unauthenticated broken access control vulnerability affecting the Montonio for WooCommerce WordPress plugin in versions up to and including 10.1.2. The flaw is categorized under [CWE-862] Missing Authorization and allows remote attackers to interact with protected plugin functionality without providing credentials. Exploitation occurs over the network, requires no user interaction, and impacts the integrity of the affected WooCommerce store. Site operators using the Montonio payment integration to process Estonian, Latvian, and Lithuanian bank payments are exposed until the plugin is updated.
Critical Impact
Remote unauthenticated attackers can invoke protected plugin functions and alter integrity-sensitive WooCommerce data without authentication or user interaction.
Affected Products
- Montonio for WooCommerce plugin versions <= 10.1.2
- WordPress sites running WooCommerce with the Montonio payment integration
- E-commerce deployments processing payments through Montonio gateways
Discovery Timeline
- 2026-06-15 - CVE-2026-48873 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2026-48873
Vulnerability Analysis
The vulnerability stems from missing authorization checks ([CWE-862]) in the Montonio for WooCommerce plugin. The plugin exposes one or more endpoints or actions that should be restricted to authenticated, privileged users, but the access control verification is either absent or improperly enforced. An unauthenticated attacker can issue HTTP requests directly to these endpoints and trigger functionality reserved for trusted roles.
The attack vector is network-based with low attack complexity. Successful exploitation does not disclose confidential data and does not cause a denial of service, but it does allow the attacker to modify state within the WooCommerce store, such as order or payment-related records handled by the Montonio integration. The Patchstack advisory tracks this issue against plugin versions up to 10.1.2.
Root Cause
The root cause is the absence of an authorization gate on sensitive plugin actions. WordPress plugins typically guard administrative or transactional endpoints with capability checks such as current_user_can() and nonce validation through check_admin_referer() or wp_verify_nonce(). In CVE-2026-48873, these checks are missing or insufficient on at least one handler, allowing any anonymous request to reach the protected code path.
Attack Vector
An attacker sends a crafted HTTP request to the vulnerable plugin endpoint exposed by the WordPress site. Because no authentication is required and no user interaction is needed, the request can be automated and executed at scale against any reachable site running an affected version. The integrity impact allows manipulation of order or payment-related data managed by the plugin. For the specific endpoint and parameters, refer to the Patchstack Vulnerability Advisory.
Detection Methods for CVE-2026-48873
Indicators of Compromise
- Anonymous HTTP POST or GET requests to Montonio plugin endpoints under /wp-admin/admin-ajax.php or /wp-json/ routes without a valid session cookie
- Unexpected modifications to WooCommerce order statuses or payment records that do not correlate with legitimate checkout sessions
- Spikes in requests targeting plugin paths from low-reputation or non-customer source IP addresses
Detection Strategies
- Inspect web server access logs for requests to Montonio plugin handlers originating from unauthenticated sessions
- Correlate WooCommerce order state changes against authenticated administrator activity to identify out-of-band modifications
- Deploy a Web Application Firewall (WAF) rule set that covers the Patchstack signature for this advisory
Monitoring Recommendations
- Enable WordPress audit logging to record order, payment, and plugin configuration changes
- Forward web server and WordPress application logs to a centralized SIEM or data lake for retention and correlation
- Alert on plugin version drift so that vulnerable instances of montonio-for-woocommerce are surfaced quickly
How to Mitigate CVE-2026-48873
Immediate Actions Required
- Update the Montonio for WooCommerce plugin to a version higher than 10.1.2 as soon as the vendor-supplied fix is available
- Audit recent WooCommerce orders and Montonio transaction logs for unauthorized state changes since installation of an affected version
- Restrict administrative and AJAX endpoints behind a WAF policy until the patched plugin version is deployed
Patch Information
A fixed release should be obtained directly from the plugin vendor or the WordPress plugin repository. Refer to the Patchstack Vulnerability Advisory for the authoritative fixed-version reference and patch notes.
Workarounds
- Temporarily disable the Montonio for WooCommerce plugin on production stores that cannot be patched immediately
- Apply virtual patching via a WAF to block unauthenticated requests to the vulnerable plugin endpoints
- Restrict access to /wp-admin/admin-ajax.php and plugin REST routes by source IP where feasible for backend-only operations
# Configuration example: WP-CLI commands to identify and remove vulnerable plugin versions
wp plugin list --name=montonio-for-woocommerce --fields=name,status,version
wp plugin update montonio-for-woocommerce
# If no patched version is yet available, deactivate the plugin:
wp plugin deactivate montonio-for-woocommerce
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
