CVE-2025-11283 is a cross-site scripting (XSS) vulnerability identified in Frappe LMS version 2.35.0, specifically within the Course Handler component. The vulnerability arises from improper sanitization or validation of the 'Description' argument, which can be manipulated by an attacker to inject malicious scripts. This flaw allows remote attackers to execute arbitrary JavaScript code in the context of the victim's browser without requiring authentication. The vulnerability is classified as medium severity with a CVSS 4.8 score, reflecting moderate impact and exploitability. The attack vector is network-based (remote), with low attack complexity, no privileges required, but user interaction is necessary for the malicious script to execute (e.g., victim visiting a crafted page). The vulnerability impacts confidentiality minimally, with limited integrity impact and no direct availability impact. The vendor was notified early about this and three other security issues, which have been fixed, but the release notes on GitHub do not explicitly mention these fixes. No public exploits are currently known to be in the wild, but the exploit details have been disclosed publicly, increasing the risk of exploitation. The lack of patch links suggests that users should verify updates directly from the vendor or repository to ensure remediation. XSS vulnerabilities like this can be leveraged to steal session cookies, perform phishing attacks, or execute actions on behalf of authenticated users, potentially leading to account compromise or data leakage within the LMS environment.

For European organizations using Frappe LMS 2.35.0, this vulnerability poses a moderate risk primarily to the confidentiality and integrity of user data. Educational institutions, corporate training departments, and other entities relying on this LMS could see unauthorized script execution leading to session hijacking, credential theft, or unauthorized actions performed with user privileges. Given the remote exploitability and the public disclosure of the vulnerability, attackers could craft malicious links or content that, when accessed by users, compromise their accounts or data. This could result in unauthorized access to sensitive educational materials, personal information of students and staff, and disruption of learning activities. While the vulnerability does not directly affect system availability, the indirect consequences such as loss of trust, regulatory non-compliance (e.g., GDPR), and potential data breaches could have significant operational and reputational impacts. Organizations with large user bases or those handling sensitive personal data are particularly at risk.

1. Immediate upgrade: Organizations should promptly upgrade Frappe LMS to the latest version where this vulnerability and related issues are confirmed fixed. If no official patch is available, consider applying vendor-recommended workarounds or temporary mitigations. 2. Input validation and sanitization: Implement additional server-side input validation and output encoding for the 'Description' field to prevent injection of malicious scripts. 3. Content Security Policy (CSP): Deploy strict CSP headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 4. User awareness: Educate users about the risks of clicking on suspicious links or content within the LMS platform. 5. Monitor logs and traffic: Implement monitoring to detect unusual activities or exploitation attempts targeting the LMS. 6. Access controls: Limit privileges of LMS users to the minimum necessary to reduce potential damage from compromised accounts. 7. Review third-party integrations: Ensure that any plugins or extensions interacting with the Course Handler component are secure and up to date.