CVE-2026-4564 identifies a code injection vulnerability in the yangzongzhuan RuoYi framework, versions 4.8.0 through 4.8.2. The flaw exists in the Quartz Job Handler component, specifically in the processing of the /monitor/job/ endpoint. The vulnerability is triggered by manipulating the invokeTarget argument, which is improperly sanitized or validated, enabling an attacker to inject malicious code. This injection can be executed remotely over the network without requiring authentication or user interaction, increasing the risk of exploitation. The vulnerability's CVSS 4.0 vector indicates a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N), with limited impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). Despite public disclosure and vendor notification, no patches or official fixes have been released, and no known exploits have been detected in the wild. The vulnerability could allow attackers to execute arbitrary code on affected systems, potentially leading to unauthorized control, data manipulation, or service disruption. The lack of vendor response and patch availability increases the urgency for organizations to implement alternative mitigations or upgrade to unaffected versions once available.

The primary impact of CVE-2026-4564 is the potential for remote code execution on systems running vulnerable versions of yangzongzhuan RuoYi. Successful exploitation could allow attackers to execute arbitrary commands, leading to full system compromise, unauthorized data access, or disruption of services. This can affect the confidentiality, integrity, and availability of affected systems. Organizations relying on RuoYi for job scheduling or monitoring may face operational disruptions, data breaches, or lateral movement within their networks. Given the vulnerability requires no authentication or user interaction, the attack surface is broad, increasing risk especially for internet-facing deployments. The absence of vendor patches and public exploit code heightens the threat, as attackers may develop exploits independently. The medium severity rating reflects the moderate impact and ease of exploitation, but the actual impact could escalate depending on the deployment context and attacker capabilities.

Until an official patch is released, organizations should implement the following mitigations: 1) Restrict network access to the /monitor/job/ endpoint using firewall rules or network segmentation to limit exposure to trusted internal users only. 2) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the invokeTarget parameter. 3) Conduct thorough input validation and sanitization on the invokeTarget argument if custom modifications are possible. 4) Monitor logs for unusual activity related to the Quartz Job Handler or /monitor/job/ endpoint to detect potential exploitation attempts. 5) Consider disabling or restricting the Quartz Job Handler component if not essential to operations. 6) Plan for an upgrade to a patched or unaffected version of RuoYi once available. 7) Maintain regular backups and incident response readiness to mitigate potential compromise consequences. These steps go beyond generic advice by focusing on specific endpoint protection and proactive detection tailored to this vulnerability.