CVE-2026-56031 Overview
CVE-2026-56031 is an unauthenticated PHP Object Injection vulnerability affecting the Uncanny Automator WordPress plugin in versions up to and including 7.3.1.2. The flaw is classified under CWE-502: Deserialization of Untrusted Data. Attackers can submit crafted serialized payloads to the plugin without authentication, triggering unsafe deserialization inside PHP. When a suitable POP (Property-Oriented Programming) gadget chain is available in the WordPress installation, exploitation can lead to code execution, file operations, or data tampering.
Critical Impact
Unauthenticated deserialization exposes affected WordPress sites to full compromise of confidentiality, integrity, and availability when a usable gadget chain exists in loaded plugins or themes.
Affected Products
- Uncanny Automator WordPress plugin versions <= 7.3.1.2
- WordPress sites running the vulnerable plugin with public network exposure
- Environments where additional plugins or themes provide exploitable PHP object gadget chains
Discovery Timeline
- 2026-06-26 - CVE-2026-56031 published to the National Vulnerability Database (NVD)
- 2026-06-26 - Last updated in NVD database
Technical Details for CVE-2026-56031
Vulnerability Analysis
The vulnerability stems from unsafe deserialization of attacker-controlled input inside the Uncanny Automator plugin. PHP Object Injection occurs when user-supplied data is passed to unserialize() without validation. During deserialization, PHP reconstructs objects and invokes magic methods such as __wakeup, __destruct, or __toString. Attackers abuse these methods by crafting object graphs that chain existing application classes into a POP gadget capable of performing dangerous operations.
Because the endpoint is reachable without authentication, any remote actor can submit the serialized payload. The impact scope depends on which classes are autoloadable at the time of deserialization inside the WordPress runtime.
Root Cause
The root cause is deserialization of untrusted data ([CWE-502]) inside a code path exposed to unauthenticated network requests. The plugin fails to validate or restrict the structure of incoming serialized data before passing it to PHP object reconstruction routines.
Attack Vector
Exploitation is performed over the network against the vulnerable WordPress endpoint exposed by Uncanny Automator. The attacker submits a crafted serialized PHP payload embedding a gadget chain drawn from classes present in WordPress core, other plugins, or themes. The high attack complexity reflects the requirement that a usable gadget chain be present in the target environment. Refer to the Patchstack advisory for advisory details.
Detection Methods for CVE-2026-56031
Indicators of Compromise
- HTTP POST or GET requests to Uncanny Automator endpoints containing serialized PHP markers such as O:, a:, or s: at the start of parameter values.
- Unexpected creation or modification of PHP files inside wp-content/uploads/ or plugin directories following external requests.
- New administrative WordPress users or option changes in wp_options without a corresponding admin session.
- Outbound connections from the PHP-FPM or web server process to unknown hosts shortly after inbound requests to the plugin.
Detection Strategies
- Inspect web server access logs for URL-encoded serialized payloads targeting Uncanny Automator routes and REST endpoints.
- Deploy web application firewall (WAF) rules matching serialized PHP object signatures on plugin URIs.
- Correlate WordPress audit logs with process-level telemetry to identify anomalous PHP child processes spawning shells or writing to disk.
Monitoring Recommendations
- Enable file integrity monitoring on the WordPress installation, particularly wp-content/plugins/uncanny-automator/.
- Forward web server, PHP error, and WordPress logs to a centralized SIEM for correlation and alerting on deserialization patterns.
- Track outbound egress from web tiers to detect post-exploitation command-and-control activity.
How to Mitigate CVE-2026-56031
Immediate Actions Required
- Upgrade Uncanny Automator to the fixed release published after version 7.3.1.2 as referenced in the Patchstack advisory.
- Audit the WordPress site for unauthorized administrator accounts, modified files, and unexpected scheduled tasks.
- Rotate WordPress secret keys in wp-config.php and reset administrator credentials if compromise is suspected.
Patch Information
Refer to the Patchstack advisory for the fixed version and vendor guidance. Apply the plugin update through the WordPress plugin manager or via WP-CLI, then verify the installed version is greater than 7.3.1.2.
Workarounds
- Disable and remove the Uncanny Automator plugin until the patched version can be deployed.
- Restrict access to WordPress admin and REST endpoints using an upstream WAF or IP allow list.
- Apply generic WAF signatures that block requests containing serialized PHP object markers on plugin URIs.
# Update Uncanny Automator using WP-CLI
wp plugin update uncanny-automator
wp plugin get uncanny-automator --field=version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
