CVE-2026-49770: WP Travel Engine Auth Bypass Vulnerability

CVE-2026-49770 Overview

CVE-2026-49770 is an unauthenticated PHP Object Injection vulnerability in the WP Travel Engine WordPress plugin affecting versions up to and including 6.7.12. The flaw stems from insecure deserialization of attacker-controlled data [CWE-502]. Remote attackers can submit crafted serialized payloads without authentication, triggering object instantiation inside the PHP application context.

When exploitable property-oriented programming (POP) gadget chains are present in the WordPress core, plugins, or themes loaded alongside WP Travel Engine, the injection can lead to arbitrary code execution, file operations, or data tampering on the host.

Critical Impact
Unauthenticated remote attackers can trigger PHP object instantiation that may chain into arbitrary code execution, full site compromise, or data exfiltration on affected WordPress sites.

Affected Products

WP Travel Engine WordPress plugin versions <= 6.7.12
WordPress installations with WP Travel Engine plugin enabled
Sites running gadget-providing plugins or themes alongside WP Travel Engine

Discovery Timeline

2026-06-15 - CVE-2026-49770 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-49770

Vulnerability Analysis

The vulnerability is an insecure deserialization issue classified under [CWE-502]. WP Travel Engine passes untrusted, attacker-supplied input into a PHP deserialization sink such as unserialize() without validating or sanitizing the input. PHP automatically instantiates objects defined in the serialized string and invokes magic methods like __wakeup(), __destruct(), or __toString() during processing.

Attackers craft serialized payloads referencing classes available in the WordPress runtime. When those classes contain dangerous logic in their magic methods, the chain becomes a POP gadget that can perform unintended operations.

Root Cause

The root cause is the use of PHP deserialization on input that crosses the unauthenticated trust boundary. The plugin accepts serialized data from HTTP request parameters and processes it before validating the structure or restricting allowed classes. PHP versions lacking allowed_classes restrictions on unserialize() calls instantiate any class present in the runtime.

Attack Vector

Exploitation requires no authentication and is delivered over the network. An attacker sends an HTTP request to a vulnerable WP Travel Engine endpoint carrying a serialized PHP object string in a parameter, cookie, or POST body. The plugin deserializes the payload, triggering gadget chains that can write files, execute PHP code, or modify database content. Successful exploitation can yield full site takeover when paired with available gadgets in the WordPress ecosystem.

No public proof-of-concept exploit is currently listed for this CVE. Refer to the Patchstack WordPress Vulnerability advisory for additional technical context.

Detection Methods for CVE-2026-49770

Indicators of Compromise

HTTP request bodies, query strings, or cookies containing serialized PHP markers such as O:, a:, or s: directed at WP Travel Engine endpoints.
Unexpected PHP files created in wp-content/uploads/ or plugin directories after requests to WP Travel Engine routes.
New or modified WordPress administrator accounts not tied to legitimate operator activity.
Outbound network connections from the web server process (php-fpm, apache2, www-data) to unknown hosts.

Detection Strategies

Inspect web server access logs for requests to WP Travel Engine handlers containing serialized object signatures.
Apply web application firewall (WAF) rules that flag serialized PHP patterns in request parameters.
Monitor file integrity in the WordPress installation directory for unexpected .php file creation or modification.
Correlate HTTP request activity with subsequent process spawns from PHP-FPM workers.

Monitoring Recommendations

Enable verbose logging on the reverse proxy or WAF in front of WordPress to capture full request bodies for forensic review.
Alert on writes to wp-config.php, .htaccess, and plugin directories outside of update windows.
Track database changes to the wp_users and wp_options tables for unauthorized modifications.

How to Mitigate CVE-2026-49770

Immediate Actions Required

Update WP Travel Engine to a version above 6.7.12 as soon as the vendor releases a patched build.
Deploy WAF rules that block serialized PHP payloads on requests targeting WP Travel Engine endpoints.
Audit the WordPress site for unauthorized administrator accounts, backdoors, and modified plugin files.
Rotate all WordPress credentials, API keys, and database passwords if compromise is suspected.

Patch Information

Consult the Patchstack advisory for WP Travel Engine for current patch availability and the fixed version. Apply the vendor-supplied update through the WordPress plugin manager once published.

Workarounds

Disable the WP Travel Engine plugin until a patched version is available if the site can tolerate the outage.
Restrict access to WP Travel Engine endpoints with IP allow-listing or authentication at the reverse proxy.
Configure PHP to harden deserialization where feasible, and remove unused plugins and themes to reduce the gadget chain surface.

bash

# Configuration example: block serialized PHP payloads at nginx
if ($request_body ~* "(O|a):[0-9]+:\"") {
    return 403;
}