External risk intelligence

Ray Remote Code Execution Vulnerability Via Browser Attack

CVE advisoryKnown Exploit

CVE-2025-62593

The vulnerability affects Ray when used as a local development tool and requires the user to inadvertently interact with malicious content via a web browser. It is not an internet-facing service, appliance, or gateway, and lacks typical public network exposure in its intended deployment context as a developer utility.

Code Injection

Anyscale Ray

before 2.52.0

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in the Ray AI compute engine, affecting developers using it as a tool. Exploitation is possible through common web browsers if a developer visits a malicious website or encounters a malvertising campaign. This could potentially allow unauthorized code execution within the development environment.

Developers using Ray can be exposed to code injection.
Critical flaw impacts development tools and requires careful review.
Confirm Ray's relevance and exposure within your development workflows.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by tricking a developer into visiting a malicious website or viewing a malicious ad while they are running Ray. This would involve a DNS rebinding attack, leveraging how browsers handle the User-Agent header, to bypass Ray's insufficient defenses and execute arbitrary code.

Developer runs Ray locally.
Developer visits a malicious website.
Remote code execution.

Live Threat

Current exploitation, exposure, and threat context

Developers using Ray as a development tool could be at risk of remote code execution. This vulnerability occurs when a developer, while using Ray, inadvertently visits a malicious website or encounters malicious advertisements through the Firefox or Safari browsers. The insufficient defense mechanism based on the User-Agent header, combined with a DNS rebinding attack, enables this exploitation.

Development environments running Ray.
Visiting malicious websites or malvertising.
Remote code execution on developer machines.

Operational Fix

Recommended remediation, mitigation, and detection steps

Given that Ray is used as a development tool, the primary responsibility likely falls on development teams or application owners who utilize Ray in their workflow. The initial practical move should be to identify all instances of Ray within the development environment, confirm if these instances are exposed to external networks, and then engage the accountable development team to assess the risk and plan remediation.

Accountable developers should own the issue.
Verify developer exposure and critical systems.
Plan updates during scheduled maintenance.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Ray software mentioned in CVE-2025-62593?

Ray is an open-source AI compute engine designed to scale Python applications. It is frequently utilized by developers as a local tool to build, train, and orchestrate machine learning workloads and distributed computing tasks on their personal or development workstations.

What is the weakness behind this Ray vulnerability?

The flaw is categorized as Code Injection (CWE-94) and Cross-Site Request Forgery (CWE-352). It exists because the software relied on checking the browser's 'User-Agent' string as a security control. This is fundamentally insecure because web standards allow that header to be easily modified, enabling attackers to bypass this guard.

How does an attacker trigger this issue?

An attacker triggers this by combining a DNS rebinding attack with the manipulated User-Agent header. This is not triggered by direct, automated scans; it requires a developer who is actively running Ray locally to navigate to a malicious website or encounter a compromised advertisement in Firefox or Safari.

Do I need to worry if Ray is not internet-facing?

Halo Surface Signal indicates that Ray is typically used as a local developer utility rather than a public-facing service, making widespread internet exploitation very unlikely. However, the risk remains if a user on that machine browses the web, as the browser acts as the bridge for the attack.

How should I respond to this CVE if I use Ray?

Your first step is to verify the version of Ray running in your development environment. If you are using any version prior to 2.52.0, you should update to 2.52.0 or later, where this defense mechanism has been corrected to prevent such browser-based exploitation.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.