CVE-2026-1129 identifies a SQL injection vulnerability in Yonyou KSOA version 9.0, specifically within the HTTP GET parameter handler of the /worksheet/worksadd.jsp file. The vulnerability is caused by insufficient input validation and sanitization of the 'ID' parameter, which allows an attacker to inject malicious SQL code remotely without requiring authentication or user interaction. This flaw enables attackers to manipulate backend database queries, potentially leading to unauthorized data disclosure, data modification, or deletion, and could also facilitate further attacks such as privilege escalation or lateral movement within the network. The vulnerability has a CVSS 4.0 base score of 6.9, categorized as medium severity, reflecting the ease of exploitation (network accessible, no privileges or user interaction needed) but limited impact scope due to partial confidentiality, integrity, and availability impact. The exploit code has been publicly disclosed, increasing the risk of exploitation, although no active exploitation has been reported to date. The vendor, Yonyou, has not responded to vulnerability disclosure requests and has not released a patch, leaving organizations reliant on mitigation strategies. Yonyou KSOA is an enterprise application platform widely used in China and among organizations with Chinese business ties, which may influence the geographic impact and threat actor interest. The vulnerability's exploitation could compromise sensitive business data and disrupt operations, emphasizing the need for immediate defensive measures.

For European organizations using Yonyou KSOA 9.0, this vulnerability poses a significant risk to the confidentiality, integrity, and availability of critical business data. Exploitation could lead to unauthorized access to sensitive information, including financial records, employee data, or intellectual property, potentially resulting in data breaches and regulatory non-compliance under GDPR. Data manipulation or deletion could disrupt business processes, causing operational downtime and financial losses. The lack of authentication and user interaction requirements makes exploitation feasible by remote attackers, increasing the threat landscape. Additionally, the public availability of exploit code raises the likelihood of opportunistic attacks or targeted campaigns against organizations relying on this software. European entities with supply chain or business dependencies involving Chinese partners may face increased exposure. The absence of an official patch necessitates reliance on compensating controls, which may not fully eliminate risk. Overall, the vulnerability could undermine trust, cause reputational damage, and incur remediation costs for affected organizations.

Given the absence of an official patch from Yonyou, European organizations should implement layered mitigation strategies. First, deploy web application firewalls (WAFs) with custom rules to detect and block SQL injection attempts targeting the 'ID' parameter in /worksheet/worksadd.jsp. Conduct thorough input validation and sanitization at the application level if source code access is available, or implement reverse proxy filtering to sanitize inputs. Restrict network access to the vulnerable endpoint by limiting exposure to trusted IP ranges and enforcing strict access controls. Monitor database logs and application logs for anomalous queries or error messages indicative of injection attempts. Employ database activity monitoring tools to detect suspicious behavior in real time. Conduct regular security assessments and penetration testing focused on injection vulnerabilities. Educate IT and security teams about this specific threat to enhance detection and response capabilities. Prepare incident response plans tailored to SQL injection exploitation scenarios. Engage with Yonyou or third-party security vendors for potential patches or workarounds and track vulnerability disclosures for updates. Consider isolating or segmenting systems running Yonyou KSOA to minimize lateral movement risk if compromised.