CVE-2025-62593 is a critical remote code execution (RCE) vulnerability affecting the Ray AI compute engine prior to version 2.52.0. The root cause is an improper control of code generation (CWE-94) combined with an insufficient defense mechanism relying on the User-Agent HTTP header starting with "Mozilla" to identify legitimate browser requests. However, the fetch specification allows modification of the User-Agent header, rendering this defense ineffective. Attackers can exploit this by conducting a DNS rebinding attack against Firefox and Safari browsers used by developers running Ray. When a developer inadvertently visits a malicious website or is served a malicious advertisement, the attacker can bypass browser-origin protections and inject malicious code into the Ray environment. This leads to remote code execution without requiring authentication, user interaction beyond visiting a malicious site, or elevated privileges. The vulnerability impacts confidentiality, integrity, and availability of the affected systems. The issue was publicly disclosed on November 26, 2025, with a CVSS 4.0 score of 9.4 (critical). Although no known exploits have been reported in the wild, the ease of exploitation and potential impact make this a severe threat. The vulnerability has been addressed in Ray version 2.52.0, which implements proper validation and mitigations against DNS rebinding and User-Agent header manipulation.

For European organizations, especially those involved in AI research and development using Ray, this vulnerability poses a significant risk. Successful exploitation can lead to full system compromise, data theft, manipulation of AI workloads, and disruption of critical AI services. The attack vector involves browser-based DNS rebinding, which can bypass network segmentation and firewall protections, potentially allowing attackers to pivot into internal development environments. This can result in intellectual property theft, sabotage of AI models, and exposure of sensitive data. The critical severity and remote exploitability without authentication increase the urgency for mitigation. Organizations relying on Firefox or Safari browsers for development are particularly vulnerable. The impact extends to cloud-based AI development environments if Ray is used there, potentially affecting multi-tenant infrastructures. Given the widespread adoption of Ray in European AI sectors, the threat could disrupt innovation and operational continuity.

1. Immediately upgrade all Ray installations to version 2.52.0 or later to apply the official patch addressing this vulnerability. 2. Implement network-level protections against DNS rebinding attacks, such as validating Host headers, restricting internal IP address access from browsers, and configuring DNS resolvers to prevent rebinding. 3. Restrict developer access to Ray services from untrusted networks and enforce strict browser security policies, including disabling or limiting JavaScript execution from untrusted sources. 4. Use browser extensions or enterprise policies to prevent User-Agent header manipulation or monitor for anomalous header values. 5. Conduct security awareness training for developers to avoid visiting untrusted websites or clicking on suspicious advertisements during development activities. 6. Monitor network traffic and logs for signs of DNS rebinding or unusual access patterns to Ray services. 7. Isolate development environments running Ray from production and sensitive networks to limit lateral movement in case of compromise. 8. Regularly review and update security controls in AI development pipelines to incorporate emerging threat intelligence.