Actively Exploited Browser-Based RCE in Ray AI Compute Engine
CISA: Ray-Project Ray Code Injection Vulnerability
CVSS 4.0
9.4critical
EPSS
17%p97
Published
()
KEV added
AI analysis
Ray, the open-source AI compute engine, is vulnerable to a critical remote code execution flaw (CVE-2025-62593, CWE-94/CWE-352) in versions prior to 2.52.0, caused by an insufficient guard against browser-based attacks: the software distinguishes browser traffic only by checking that the User-Agent header starts with 'Mozilla', but the fetch specification allows that header to be modified. An attacker can combine DNS rebinding with a crafted User-Agent so that a developer's Firefox or Safari browser silently sends malicious requests to locally running Ray services after the developer visits an attacker-controlled website or is served a malicious advertisement (malvertising). Successful exploitation yields full remote code execution on the machine running Ray, with high confidentiality, integrity and availability impact reflected in the CVSS 4.0 score of 9.4. Affected users are developers running Ray as a development tool on any version before 2.52.0, which is the fixed release. The flaw is being actively exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-17, a public proof of concept is available in the project's GitHub security advisory (GHSA-q279-jhrf-cc6v), and EPSS estimates a 16.9% probability of exploitation in the next 30 days.
What to do: Upgrade Ray to version 2.52.0 or later immediately, in line with CISA KEV and BOD 26-04 patching requirements. Until patched, avoid browsing untrusted websites (including ad-serving pages) while Ray development services are running, and restrict network access to locally running Ray services. Focus triage on machines where developers use Firefox or Safari alongside Ray, and hunt for signs of compromise since the flaw is actively exploited.
Affected
Ray-Project (Anyscale) Ray
All versions prior to 2.52.0 (patched in 2.52.0)
Estimated exposure
largeTens of thousands of developer machines/environments running vulnerable Ray (estimate) — No install counts or internet-exposure scan data were provided, so the order of magnitude is based on deployment patterns: Ray is a widely used open-source AI compute framework, but exploitation additionally requires a developer to be…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
Ray is an AI compute engine. Prior to version 2.52.0, developers working with Ray as a development tool can be exploited via a critical RCE vulnerability exploitable via Firefox and Safari. This vulnerability is due to an insufficient guard against browser-based attacks, as the current defense uses the User-Agent header starting with the string "Mozilla" as a defense mechanism. This defense is insufficient as the fetch specification allows the User-Agent header to be modified. Combined with a DNS rebinding attack against the browser, and this vulnerability is exploitable against a developer running Ray who inadvertently visits a malicious website, or is served a malicious advertisement (malvertising). This issue has been patched in version 2.52.0.
CISA Known Exploited Vulnerability
Affected
Ray-Project Ray
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA added actively exploited Ray flaw CVE-2025-62593 (CVSS 9.4) to its KEV catalog; the DNS rebinding RCE has powered crypto-mining and DDoS botnet campaigns.
CISA added CVE-2025-62593 (CVSS 9.4) to its Known Exploited Vulnerabilities catalog, citing active exploitation of a DNS rebinding-driven RCE flaw in the Ray distributed computing framework, fixed in version 2.52.0. The flaw stems from missing authentication on critical Ray endpoints and an insufficient User-Agent header guard, exploitable against developers running Ray in Firefox or Safari via malicious websites or ads. RondoDox botnet operators incorporated the PoC exploit before the November 26, 2025 disclosure, and unpatched GPU-equipped clusters were hijacked into self-replicating crypto-mining botnets in the ShadowRay 2.0 campaign. FCEB agencies must apply fixes by August 20, 2026.
CISA added actively exploited Ray RCE flaw CVE-2025-62593 (CVSS 9.4) to its KEV catalog, ordering federal agencies to patch by August 20, 2026.
CISA added CVE-2025-62593 (CVSS 9.4), a critical remote code execution flaw in the Ray AI compute engine, to its Known Exploited Vulnerabilities catalog with a due date of August 20, 2026. Versions before 2.52.0 relied on a User-Agent header check to guard the dashboard/API, which combined with DNS rebinding allows arbitrary code execution on developers' machines via malicious websites or ads. Aviatrix's analysis describes privilege escalation, lateral movement, command and control, and data exfiltration following exploitation. Federal civilian agencies must remediate under BOD 22-01; the flaw affects Firefox and Safari.
Insikt Group catalogs 73 high-impact August 2026 CVEs (43 Very Critical), including PaperCut, Zimbra, and Metabase flaws actively exploited or weaponized.
Recorded Future's Insikt Group identified 73 high-impact vulnerabilities in August 2026, 43 rated Very Critical, spanning 45 vendors with Microsoft accounting for roughly 11%. 31 vulnerabilities surfaced via CISA's KEV catalog, with others validated via open sources, vendor telemetry, and honeypot data. New Nuclei detection templates were released for CVE-2025-62593 (Ray), CVE-2026-72898 (Metabase), and CVE-2026-9198 (IBM Langflow). The report also highlights two AI-assisted operations: UAT-10147 exploited Zimbra, AjaxPro, Nacos, and Telerik servers before using DeepAudit and PentestGPT post-compromise, while a separate Chinese-speaking actor weaponized Hermes Agent and DeepSeek in a failed attempt.