CVE-2026-116370 in Sid Meier's Civilization VI
Summary
by MITRE • 10/26/2026
A security flaw has been discovered in 2K Games Sid Meier's Civilization IV 1.0.12.68. The affected element is the function loadstring of the component Lua sandbox. Performing a manipulation results in type confusion. The attack may be initiated remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure.
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Analysis
by VulDB Data Team • 10/27/2026
The discovery of a critical vulnerability within 2K Games Sid Meier's Civilization IV version 1.0.12.68 highlights significant security deficiencies in legacy game software that continues to maintain an active player base despite its age. The core issue resides within the Lua sandbox component, specifically affecting the loadstring function which is responsible for parsing and executing dynamic code strings at runtime. This architectural decision allows for flexible gameplay modifications but introduces a severe risk when input validation is insufficient. The vulnerability manifests as a type confusion error, where the application fails to correctly distinguish between different data types during execution. This misclassification leads to improper memory handling or logic flow deviations that can be exploited by an attacker who provides specifically crafted inputs designed to trigger this state of ambiguity within the interpreter engine.
From a technical perspective, type confusion vulnerabilities are particularly dangerous because they undermine the fundamental assumptions made by both the compiler and the runtime environment regarding data integrity. In the context of Civilization IV's Lua implementation, the loadstring function likely processes user-generated content or mod scripts without rigorous type checking before execution. When an attacker manipulates these inputs to present a value that is interpreted as one type in some contexts but another in others, it can lead to arbitrary code execution. This occurs because the misinterpreted data may overwrite critical memory structures or redirect control flow to malicious shellcode embedded within the crafted input string. The presence of such a flaw indicates that the sandboxing mechanisms intended to isolate game logic from system-level operations are either bypassed entirely or rendered ineffective due to this internal inconsistency in type handling.
The operational impact of this vulnerability is severe given its remote exploitability and the availability of public proof-of-concept code. Since Civilization IV supports multiplayer interactions, an attacker can initiate attacks remotely by tricking a victim into loading a malicious map file, mod script, or network packet containing the exploitable payload. The release of the exploit to the public significantly lowers the barrier for entry, allowing less sophisticated threat actors to leverage this flaw against unsuspecting players. Successful exploitation could result in full system compromise on the affected machine, leading to data theft, installation of malware, or use of the compromised host as part of a botnet. This represents a high-risk scenario where entertainment software becomes an attack vector for broader cybercriminal activities targeting legacy systems that may lack modern security patches and endpoint protection capabilities.
This vulnerability aligns with CWE-843 which describes access to incorrect type during interpretation, a common pitfall in dynamically typed languages like Lua when strict typing is not enforced by the host application or sandbox environment. Furthermore, from an offensive cybersecurity framework perspective such as MITRE ATT&CK, this flaw facilitates techniques associated with initial code execution and potentially privilege escalation depending on the context of the game client's permissions. The ability to execute arbitrary commands remotely places it in categories related to remote service exploitation where untrusted data is processed without adequate validation. Organizations and individuals continuing to use this software must recognize that while the primary function is gaming, the underlying engine processes executable code from potentially untrusted sources, making standard security hygiene insufficient against targeted attacks leveraging such specific logic errors.
Mitigation strategies for this vulnerability are limited by the age of the software and the likelihood of a vendor patch being issued given the release cycle of Civilization IV. The most effective immediate countermeasure is to disable or restrict the loading of user-generated content, mods, and networked map files that contain Lua scripts unless they have been verified as safe through strict manual review. Users should avoid joining multiplayer sessions with unknown participants who may distribute malicious assets designed to trigger this type confusion flaw. Additionally, running the game within a restricted virtual machine environment or using application whitelisting tools can help contain any potential exploitation attempts by limiting the system-level access granted to the Civilization IV process. Long-term resolution requires migrating away from unsupported legacy software versions that lack modern security controls and relying on community patches if available that address these specific interpreter flaws in the Lua sandbox implementation.