CVE-2025-59986 is an XSS vulnerability classified under CWE-79 affecting Juniper Networks Junos Space, a network management platform widely used to manage Juniper network devices. The vulnerability arises from improper neutralization of user-supplied input during web page generation, specifically in the Model Devices input fields. Attackers can inject malicious script tags that are stored and later executed when another user accesses the affected page. This stored XSS enables execution of arbitrary scripts with the permissions of the viewing user, including administrators, potentially allowing unauthorized command execution or session hijacking. The vulnerability affects all versions of Junos Space prior to 24.1R4. Exploitation requires no authentication but does require the victim to interact by visiting the compromised page. The CVSS 3.1 base score is 6.1, reflecting network attack vector, low attack complexity, no privileges required, but user interaction is necessary. The scope is changed (S:C) because the vulnerability can affect resources beyond the vulnerable component. No public exploits are known yet, but the risk remains significant due to the administrative context of the affected platform.

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of network management operations. Successful exploitation could allow attackers to execute arbitrary commands or scripts with administrative privileges, potentially leading to unauthorized configuration changes, data leakage, or disruption of network services. Given Junos Space’s role in managing critical network infrastructure, exploitation could cascade into broader operational impacts, including service outages or compromised network security posture. The vulnerability’s medium severity and requirement for user interaction mean targeted phishing or social engineering attacks could be used to trick administrators into triggering the exploit. Organizations in sectors such as telecommunications, finance, government, and critical infrastructure that rely on Juniper network devices and Junos Space are particularly at risk. The lack of known exploits in the wild provides a window for proactive mitigation before active attacks emerge.

1. Apply the official Juniper Networks patch by upgrading to Junos Space version 24.1R4 or later as soon as it becomes available. 2. Implement strict input validation and sanitization on all user-supplied data fields within Junos Space, especially Model Devices input areas, to prevent script injection. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts within the Junos Space web interface. 4. Limit administrative access to Junos Space interfaces using network segmentation, VPNs, and multi-factor authentication to reduce exposure to potential attackers. 5. Educate administrators and users about the risks of clicking on untrusted links or visiting suspicious pages within the management console. 6. Monitor Junos Space logs and network traffic for unusual activity that could indicate attempted exploitation. 7. Consider deploying web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting Junos Space. 8. Regularly review and audit user permissions to ensure the principle of least privilege is enforced.