CVE-2026-3968 is a code injection vulnerability affecting AutohomeCorp's frostmourne product up to version 1.0. The vulnerability is located in the scriptEngine.eval function of the ExpressionRule.java file, which utilizes the Oracle Nashorn JavaScript Engine. The flaw stems from insufficient validation or sanitization of the EXPRESSION argument passed to the eval function, allowing an attacker to inject malicious JavaScript code. Since the Oracle Nashorn engine executes JavaScript within the Java Virtual Machine, successful exploitation can lead to arbitrary code execution on the host system. The attack vector is remote, requiring no authentication or user interaction, making it easier for attackers to exploit. The vendor was notified early but has not responded or released patches, and the exploit details have been publicly disclosed, increasing the risk of exploitation. The CVSS 4.0 score is 5.3 (medium), reflecting the moderate complexity and impact. The vulnerability affects confidentiality, integrity, and availability, as arbitrary code execution can lead to data theft, system manipulation, or denial of service. No known active exploits have been reported yet, but the public disclosure means attackers could develop exploits rapidly. The lack of vendor response and patch availability necessitates immediate mitigation efforts by users of frostmourne 1.0.

The vulnerability allows remote attackers to execute arbitrary code on systems running frostmourne 1.0, potentially compromising the confidentiality, integrity, and availability of affected systems. Attackers could leverage this to steal sensitive data, manipulate system operations, deploy malware, or disrupt services. Since no authentication or user interaction is required, the attack surface is broad, increasing the likelihood of exploitation. Organizations relying on frostmourne for critical functions may face operational disruptions, data breaches, or lateral movement within networks. The absence of vendor patches exacerbates the risk, forcing organizations to rely on workarounds or mitigations. The medium severity score indicates a moderate but significant threat, especially in environments where frostmourne is exposed to untrusted networks. The public disclosure of exploit details further elevates the urgency to address this vulnerability.

1. Immediately isolate and restrict network access to systems running frostmourne 1.0, especially from untrusted or external networks. 2. Implement strict input validation and sanitization at any integration points or interfaces that pass expressions to the scriptEngine.eval function, if possible through configuration or custom wrappers. 3. Employ runtime application self-protection (RASP) or Web Application Firewalls (WAFs) with custom rules to detect and block suspicious script injection patterns targeting the vulnerable eval function. 4. Monitor system and application logs closely for unusual script execution or errors related to ExpressionRule.java or the Nashorn engine. 5. Consider deploying host-based intrusion detection/prevention systems (HIDS/HIPS) to detect anomalous process behaviors indicative of code injection. 6. If feasible, upgrade to a newer, unaffected version of frostmourne once available or replace the vulnerable component with an alternative that does not use Oracle Nashorn or has patched this vulnerability. 7. Maintain strict privilege separation and run frostmourne with the least privileges necessary to limit the impact of potential exploitation. 8. Prepare incident response plans specifically addressing code injection and remote code execution scenarios related to this vulnerability.