CVE-2026-112859 in Little Birdies Plugin
Summary
by MITRE • 10/23/2026
Deserialization of Untrusted Data vulnerability in ThemeREX Group Little Birdies little-birdies allows Object Injection.This issue affects Little Birdies: from n/a through 1.3.16.
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Analysis
by VulDB Data Team • 10/23/2026
The vulnerability identified as a deserialization of untrusted data flaw within the ThemeREX Group Little Birdies plugin, specifically affecting versions up to and including 1.3.16, represents a critical security risk rooted in improper handling of serialized objects. This class of vulnerabilities occurs when an application accepts user-supplied input that is then passed directly into PHP's unserialize function or similar deserialization mechanisms without adequate validation or sanitization. In the context of WordPress plugins like Little Birdies, this often manifests when data retrieved from database fields, POST requests, or other external sources is assumed to be safe and immediately processed as a serialized object structure. The core technical flaw lies in the absence of strict type checking or allow-listing for expected classes during the deserialization process, which allows an attacker to inject maliciously crafted serialized payloads that can instantiate arbitrary PHP objects with controlled properties.
From a technical perspective, this vulnerability enables Object Injection, a severe subset of insecure deserialization attacks. When an application deserializes untrusted data, it reconstructs PHP objects in memory based on the structure provided by the input. If the attacker controls the content of these serialized strings, they can manipulate object states or trigger specific magic methods such as __wakeup(), __destruct(), or __toString() that are defined within vulnerable classes. These methods often execute code automatically upon deserialization, providing a direct execution path for remote attackers. The impact is particularly acute in WordPress environments where the plugin may have access to sensitive administrative functions, database credentials, or file system operations, thereby amplifying the potential damage of successful exploitation.
The operational impact of this vulnerability is significant, as it can lead to full server compromise if exploited effectively. An attacker could leverage Object Injection to achieve Remote Code Execution (RCE), allowing them to execute arbitrary commands on the underlying web server with the privileges of the web application process. This level of access facilitates further lateral movement within the network, data exfiltration, and persistence mechanisms such as backdoor installation. Furthermore, because Little Birdies is a WordPress plugin, successful exploitation could also lead to unauthorized administrative actions, defacement of the website, or use of the compromised server for distributed denial-of-service attacks against third parties. The vulnerability affects all versions from n/a through 1.3.16, indicating that any installation running these older versions remains exposed until patched.
This flaw aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-502 Deserialization of Untrusted Data and CWE-94 Improper Control of Generation of Code PHP Object Injection. In terms of the MITRE ATT&CK framework, this vulnerability supports techniques related to Initial Access via Web Application Exploitation and Execution through Command and Scripting Interpreter if RCE is achieved. The attack vector typically involves crafting a malicious serialized payload that exploits specific class methods available in the plugin's codebase or its dependencies, requiring no authentication if the vulnerable endpoint is publicly accessible, though authenticated attacks are also possible depending on where the deserialization occurs within the plugin logic.
Mitigation strategies must prioritize immediate remediation through software updates. Administrators should upgrade Little Birdies to version 1.3.17 or later, which presumably includes fixes for this insecure deserialization issue by implementing proper validation of input data before it is passed to any unserialization functions. If upgrading is not immediately feasible, temporary mitigations include disabling the plugin entirely if its functionality is not critical to business operations. Additionally, deploying a Web Application Firewall (WAF) with rules designed to detect and block malicious serialized payloads can provide an additional layer of defense by inspecting HTTP request bodies for patterns indicative of object injection attempts. It is also advisable to review server-side configurations to restrict the execution capabilities of PHP functions that are commonly abused in such attacks, although this should be viewed as a compensating control rather than a primary fix. Regular security audits and code reviews focusing on input validation practices are essential to prevent similar vulnerabilities from being introduced in future updates or other plugins within the WordPress ecosystem.