CVE-2026-112848 in Hostme Plugin
Summary
by MITRE • 10/23/2026
Deserialization of Untrusted Data vulnerability in AivahThemes Hostme v2 hostmev2 allows Object Injection.This issue affects Hostme v2: from n/a through 7.0.
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Analysis
by VulDB Data Team • 10/24/2026
The identified vulnerability represents a critical security flaw within the AivahThemes Hostme application, specifically affecting version 2 and extending through version 7.0 of hostmev2. This issue is classified as an Object Injection resulting from the deserialization of untrusted data. In software architecture, serialization is commonly used to convert complex objects into a byte stream for storage or transmission, while deserialization reverses this process to reconstruct the object in memory. When an application accepts serialized data from external sources without proper validation or integrity checks, it creates a pathway for attackers to manipulate the internal state of the application during the reconstruction phase. This specific vulnerability allows an attacker to inject malicious objects into the system's execution context by exploiting weaknesses in how Hostme processes incoming serialized payloads.
From a technical perspective, this flaw falls under the category of CWE-502, which denotes Deserialization of Untrusted Data. The core mechanism involves the application trusting input data that has been encoded or serialized without verifying its origin or content integrity. When the deserialization function is invoked on this unverified data, it may instantiate classes and execute methods defined within those objects automatically. If an attacker can control the structure of the serialized payload, they can craft a malicious object that triggers unintended side effects when instantiated. This often involves leveraging gadget chains—sequences of existing application code or library functions—that perform dangerous operations such as arbitrary file writes, remote command execution, or privilege escalation. The vulnerability is particularly severe because it bypasses traditional input validation mechanisms since the data appears to be in a standard serialized format rather than raw user input like SQL queries or HTML scripts.
The operational impact of this vulnerability is profound and potentially catastrophic for systems running affected versions of Hostme. Successful exploitation can lead to Remote Code Execution, allowing an attacker to take full control over the underlying server environment. Beyond code execution, attackers may achieve unauthorized access to sensitive data stored within the application's memory or database by manipulating object states that dictate user roles or permissions. This could result in complete compromise of confidentiality, integrity, and availability. For instance, an attacker might alter session objects to escalate privileges from a standard user to an administrator, thereby gaining unrestricted access to administrative functions. Additionally, if the deserialized data influences file system operations, it could lead to arbitrary file read or write vulnerabilities, enabling further lateral movement within the network infrastructure.
This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly those related to Initial Access and Execution. The exploitation technique mirrors patterns seen in attacks like T1059 Command and Scripting Interpreter if code execution is achieved, or T1203 Exploitation for Client Execution depending on the vector of delivery. It also relates to privilege escalation techniques where object manipulation alters access controls. Defenders should recognize that this type of vulnerability often requires specific application logic flaws rather than simple network-level exploits, making it a high-value target for advanced persistent threats seeking long-term footholds in enterprise environments.
Mitigation strategies must focus on eliminating the root cause by avoiding deserialization of untrusted data whenever possible. If serialization is necessary for functionality, developers should implement strict input validation and integrity verification mechanisms such as digital signatures or HMACs to ensure that serialized payloads have not been tampered with during transit. Additionally, using safe alternatives like JSON instead of native object serialization formats can significantly reduce the attack surface since JSON parsers typically do not instantiate arbitrary objects. For organizations currently running vulnerable versions of Hostme from n/a through 7.0, immediate patching is essential as vendor updates likely address these deserialization checks. In cases where updating is not immediately feasible, deploying web application firewalls with rules designed to detect and block suspicious serialized payloads can provide a layer of defense-in-depth while longer-term remediation plans are executed.