Ray Dashboard Browser Drive-by RCE
- Product
- Anyscale Ray
- CVE
- CVE-2025-62593
- Disclosed
- 2025-11-26
- CVSS
- 8.8
- Auth
- pre-auth
- CISA KEV
- yes
- Affected
- Ray < 2.52.0
- Fixed
- 2.52.0
Summary
Developers running Ray locally could be compromised just by visiting a malicious website in Firefox or Safari. Ray's only defense against browser requests was a User-Agent check that browsers let scripts override. CISA added it to KEV in August 2026.
Root cause
Ray blocked browser-originated requests to sensitive dashboard APIs by rejecting User-Agent values starting with 'Mozilla'. The Fetch specification allows scripts to set a custom User-Agent, so combined with DNS rebinding a malicious page could reach the localhost dashboard and submit jobs that run arbitrary commands.
Impact
Remote code execution on a developer workstation or cluster via a web page or malvertising.
Detection
Version check for Ray < 2.52.0; look for job submissions with unusual User-Agents or Host headers that do not match the local address (DNS rebinding).
Mitigation
Upgrade to Ray 2.52.0+ and enable token authentication; bind the dashboard to localhost only.