200,000
Ray deployments exposed to the internet and vulnerable to unauthenticated RCE, per BitSight research from March 2026
9.4
CVSS score of CVE-2025-62593, the critical Ray DNS rebinding RCE added to CISA KEV on August 18 with a 48-hour federal patch deadline
$3M+
Annual on-demand GPU compute value of one NVIDIA A100 cluster compromised by ShadowRay 2.0, per Oligo Security analysis
240 GB
Compressed source code, AI models, and database credentials exfiltrated by attackers from a single compromised Ray cluster

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CVE-2025-62593, a CVSS 9.4 critical remote code execution flaw in the Ray distributed computing framework, was confirmed actively exploited and added to the CISA Known Exploited Vulnerabilities catalog today, with a mandatory federal patch deadline of August 20, just 48 hours from now.

Ray is an open-source Python framework developed by Anyscale that organizations use to distribute AI and machine learning workloads across clusters of servers and GPUs. Over 200,000 Ray deployments remain exposed to the internet, according to BitSight research from March 2026, a 10x increase from the initial count in 2024. Every one of those exposed deployments is vulnerable to unauthenticated remote code execution by any attacker who can reach port 8265, the default Ray dashboard port.

The vulnerability stems from Ray's decision to deploy its Job API endpoints without authentication. The /api/jobs and /api/job_agent/jobs/ endpoints accept arbitrary job submissions from any source. CVE-2025-62593 documents how attackers bypass Ray's only defense against browser-based access, a User-Agent header check, using a DNS rebinding attack against Firefox and Safari users. This allows a malicious website to proxy job submissions through a victim's browser to Ray instances that are not directly internet-exposed, dramatically expanding the attack surface beyond the 200,000 directly accessible clusters.

Two active threat campaigns are exploiting this flaw right now. The RondoDox DDoS botnet weaponized CVE-2025-62593 as a zero-day, incorporating the exploit two days before Anyscale publicly disclosed the vulnerability in November 2025. The ShadowRay 2.0 campaign, documented by Oligo Security, has been running continuously since September 2024, converting compromised Ray clusters into a self-propagating cryptocurrency mining botnet that has stolen GPU compute resources worth millions of dollars and exfiltrated 240 gigabytes of AI model data from a single compromised cluster.

How Does CVE-2025-62593 DNS Rebinding RCE Work?

CVE-2025-62593 exploits two overlapping weaknesses in Ray's API security model: the absence of authentication on the Job API and an insufficient browser-origin check.

The Ray dashboard exposes a web-based Job API at /api/jobs and /api/job_agent/jobs/. These endpoints accept arbitrary Python or shell code submissions without requiring any credentials. Anyscale's original design assumed Ray would be deployed in isolated network environments and operated by trusted users, so no authentication gate was added to the API layer. The only defense against external browser access was a User-Agent header check requiring requests to start with "Mozilla."

DNS rebinding attacks bypass this check by convincing a victim's browser to make requests on the attacker's behalf. The attack proceeds in four steps. An attacker registers a malicious domain and sets a very short DNS TTL. The victim visits the attacker's page in Firefox or Safari, and the page begins executing JavaScript. The attacker's DNS server then re-resolves the same hostname to the Ray cluster's local IP address. On subsequent JavaScript requests, the browser believes it is communicating with the original domain, satisfying the same-origin policy, but the requests now reach the Ray cluster directly. The JavaScript sends a properly formed User-Agent header starting with "Mozilla," passing Ray's check, and the cluster executes the submitted job as the Ray process.

Attackers targeting directly internet-exposed Ray clusters skip the DNS rebinding step entirely and submit jobs directly to the unauthenticated API. This is the technique the ShadowRay 2.0 campaign uses against the 200,000 publicly exposed Ray servers. A single HTTP POST to /api/jobs with a bash payload is sufficient for full cluster compromise with no credentials or user interaction required.

The result in both cases is arbitrary command execution on the Ray head node and, through Ray's native job scheduling API, on every worker node in the cluster. The Langflow CVE-2026-9198 unauthenticated RCE followed an identical pattern of an AI framework API endpoint with no authentication gate, reinforcing this as a systemic category risk across the AI tooling ecosystem.

ShadowRay 2.0: The Self-Propagating GPU Mining Botnet

ShadowRay 2.0 is an active global campaign documented by Oligo Security in November 2025 that exploits exposed Ray clusters to build a self-replicating cryptocurrency mining botnet. The campaign operator, identified as IronErn440, has been active since at least September 2024, targeting over 200,000 publicly accessible Ray deployments across multiple continents.

The attack begins with passive reconnaissance. IronErn440 submits test jobs to /api/jobs/ using Ray's legitimate job API, triggering DNS and HTTP callbacks to interact.sh infrastructure at oast.fun to identify which Ray instances are alive and accessible. For confirmed targets, attackers submit multi-stage Bash and Python payloads that establish persistence and deploy the full attack toolkit.

Post-exploitation establishes four capabilities simultaneously. XMRig v6.16.4 mines Monero through pool.supportxmr.com on port 443 to blend mining traffic with HTTPS. The Rigel GPU miner targets NVIDIA CUDA devices. Sockstress, a TCP state exhaustion tool, transforms infected clusters into DDoS weapons targeting other mining pools. Ray's NodeAffinitySchedulingStrategy is then weaponized to enumerate all cluster nodes and pin malicious jobs to each one, spreading the infection laterally across the entire cluster without additional exploits.

To avoid detection, IronErn440 limits CPU usage to approximately 60% and hides GPU memory consumption from Ray's native monitoring. Malicious processes are renamed: XMRig runs as kworker/0:0 (masquerading as a Linux kernel worker), .python3.6 (hidden with a leading dot), and dns-filter (appearing as a system service). A competing miner elimination script also runs, killing any XMRig processes not connected to IronErn440's preferred pool and blocking competing pools via /etc/hosts and iptables.

One compromised cluster documented by Oligo contained NVIDIA A100 GPUs with an annual on-demand value exceeding three million dollars. Attackers accessed and exfiltrated a 240-gigabyte compressed archive from this cluster containing source code, AI model weights, training datasets, and database credentials. Stolen AI model weights represent competitive intelligence worth months of GPU training compute. The LLMjacking AI compute theft campaign documented earlier this year followed a similar pattern, though targeting API keys rather than direct cluster access.

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Indicators of Compromise: Is Your Ray Cluster Already Hit?

Compromised Ray clusters show characteristic signs across four categories. Check all of them before and after patching. If a cluster was exposed before today's CISA KEV announcement, treat it as potentially compromised until you have completed a full forensic sweep.

Network indicators: Block outbound connections to the following IPs at your perimeter firewall immediately. Any DNS query for pool.supportxmr.com or eu.zano.k1pool.com from a Ray cluster node confirms active cryptocurrency mining. Block both mining pool domains at your DNS resolver in addition to the firewall.

Process masquerade indicators: Run ps aux on each Ray worker node and search for processes named kworker/0:0, dns-filter, and .python3.6. Legitimate Linux kernel worker threads do not use static notation in the format kworker/0:0 under standard scheduling. Legitimate Python processes do not prefix their name with a dot. Any hit on these names warrants immediate process termination and forensic review of the executable path.

Persistence indicators: Run crontab -l on all Ray nodes and examine /etc/cron.d/ for entries that download and pipe shell scripts from GitHub or GitLab repositories. IronErn440's cron persistence executes every 15 minutes. Also check .bashrc for injected commands and systemd unit files under /etc/systemd/system/ for unfamiliar services.

Data exfiltration indicators: Review recent large archive creation events on Ray head nodes. Check cloud storage (S3, GCS, Azure Blob) access logs for high-volume data reads that do not match normal application traffic patterns. Review MySQL and PostgreSQL access logs for query patterns inconsistent with your application's normal behavior.

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Sigma Detection Rules for CVE-2025-62593 Ray RCE

No CVE-specific Sigma rule for CVE-2025-62593 exists in the SigmaHQ library yet. The vulnerability was added to the CISA KEV catalog today, and community rules for AI framework CVEs typically lag the disclosure date by three to six weeks. The two rules below target the post-exploitation behavior that is consistent across ShadowRay 2.0 infections: outbound DNS queries to Monero mining pools and suspicious cron job modifications on Linux nodes.

The Monero mining pool DNS rule is status:stable and operates on DNS query logs. Deploy it in your SIEM against DNS resolver logs or network packet capture from Ray cluster nodes. This rule explicitly covers pool.supportxmr.com, the primary mining pool used by ShadowRay 2.0.

The Linux cron job rule requires process execution telemetry from Ray nodes. Enable auditd or deploy osquery to capture execve syscalls for crontab process creation. ShadowRay 2.0's 15-minute cron persistence generates consistent crontab activity; any crontab invocation from a Ray cluster node is a high-priority signal requiring immediate investigation.

The WAF rules below target CVE-2025-62593 at the HTTP layer. The exploit arrives as an unauthenticated POST or GET to /api/jobs or /api/job_agent/jobs/ endpoints. Deploy any reverse proxy or WAF in front of Ray dashboards in count or log mode first to establish a legitimate traffic baseline before switching to block mode.

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Remediation: Patch Ray to 2.52.0 Before August 20

Apply the following steps in order. The patch is the critical action. All other steps harden against re-exploitation and address potential existing compromise.

Apply official patch →github.com/ray-project/ray/releases/tag/ray-2.52.0

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Why CVE-2025-62593 Matters for Your AI Infrastructure

CVE-2025-62593 represents a systemic category of risk that is accelerating as AI infrastructure scales: compute APIs designed for trusted networks deployed without authentication in environments that are no longer isolated.

Ray's design decision to trust its network environment made sense when distributed computing clusters were isolated research infrastructure. Modern AI development workflows do not match that assumption. Developers run Ray locally on laptops connected to corporate networks, researchers spin up Ray clusters on cloud instances with default security group configurations, and enterprises deploy Ray for production AI serving with management interfaces accessible for operational convenience. The 200,000 exposed Ray instances BitSight identified in March 2026 represent a 10x increase from the 2024 baseline, tracking exactly with AI adoption growth.

The compute and data value in a Ray cluster is substantial. OpenAI, major financial institutions running quantitative model backtesting, and healthcare organizations running drug discovery AI all use Ray at scale. NVIDIA A100 clusters routinely exceed three million dollars in annual on-demand compute cost. AI model weights represent months of training time and competitive intelligence. The ShadowRay 2.0 campaign documented by Oligo monetizes this directly: stolen GPU cycles for cryptocurrency, stolen model weights for IP theft or competitive intelligence, stolen database credentials for further access.

The federal August 20 deadline signals assessed exploitation risk in the immediate term. The 48-hour window CISA set is among the shortest deadlines in the KEV catalog this year, reflecting confirmed active exploitation by multiple threat actors with public exploit code available. Every organization running Ray, regardless of federal affiliation, should treat the August 20 date as an operational deadline and complete the patch and network isolation steps today.

Attackers are turning AI compute infrastructure itself into a weapon -- first stealing GPU cycles, then exfiltrating the models those GPUs trained.

Oligo Security, ShadowRay 2.0 Campaign Analysis, November 2025

The bottom line

CVE-2025-62593 in Ray grants unauthenticated remote code execution on AI compute clusters through a DNS rebinding attack on the Job API. CISA added it to the Known Exploited Vulnerabilities catalog today with a 48-hour federal patch deadline of August 20. Over 200,000 Ray deployments remain exposed. Two active campaigns, RondoDox and ShadowRay 2.0, are exploiting this flaw right now to steal GPU compute, mine Monero, and exfiltrate AI model weights. Upgrade to Ray 2.52.0, block external access to ports 8265 and 8266, block the ShadowRay C2 IPs, and hunt for kworker/0:0 and dns-filter process masquerades on all Ray nodes before August 20.

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Frequently asked questions

What is CVE-2025-62593?

CVE-2025-62593 is a CVSS 9.4 critical remote code execution vulnerability in Anyscale Ray, an open-source Python framework for distributed AI and machine learning workloads. The flaw stems from Ray deploying its Job API endpoints without authentication. An attacker who can reach the Ray dashboard on port 8265 can submit arbitrary shell code for execution on the cluster without any credentials. The DNS rebinding component allows attackers to exploit Ray instances that are not directly internet-facing by using a victim's browser as a proxy through Firefox or Safari. Ray 2.52.0 resolves the vulnerability.

How does the DNS rebinding attack work against Ray?

A DNS rebinding attack against Ray starts with a victim visiting a malicious website while running Ray locally. The attacker controls a domain with a very short DNS TTL. The victim's browser initially resolves the domain to the attacker's server. The attacker then changes the DNS record to resolve to the Ray cluster's local IP address. On subsequent requests, the browser applies same-origin policy to the local IP, allowing JavaScript on the malicious page to submit jobs to Ray's unauthenticated API. Ray's only browser check, a User-Agent header requirement starting with Mozilla, is trivially bypassed because the fetch specification allows User-Agent manipulation.

Is Ray safe to run on an internet-facing server?

No. Ray's Job API endpoints are unauthenticated by design and must be isolated from untrusted networks regardless of the CVE-2025-62593 patch status. Anyscale's documentation states Ray should run in isolated network environments with trusted users. Over 200,000 Ray deployments are internet-exposed, representing a widespread misconfiguration. Upgrading to Ray 2.52.0 fixes the DNS rebinding bypass but does not add authentication to the Job API. Block external access to Ray ports 8265, 8266, and 10001 at the firewall or cloud security group level in addition to applying the patch.

How do I patch Ray to fix CVE-2025-62593?

Run pip install 'ray==2.52.0' on the Ray head node and all worker nodes, then restart the Ray cluster. For containerized deployments, update the Ray base image tag to 2.52.0 and redeploy. For Kubernetes deployments using KubeRay, update the rayVersion field in your RayCluster manifest to 2.52.0 and apply the change. Verify the upgrade with python -c 'import ray; print(ray.__version__)'. Federal civilian agencies must complete this remediation by August 20, 2026 per CISA Binding Operational Directive 22-01.

What is ShadowRay 2.0?

ShadowRay 2.0 is an active global campaign documented by Oligo Security in November 2025 that exploits exposed Ray clusters to build a self-propagating cryptocurrency mining botnet. The campaign operator, identified as IronErn440, has been active since September 2024. ShadowRay 2.0 submits jobs to exposed Ray clusters via the unauthenticated Job API, deploys XMRig and Rigel miners targeting NVIDIA GPUs, establishes 15-minute cron-based persistence, and uses compromised clusters to scan for and infect new Ray instances. The campaign also steals AI models, datasets, and database credentials from infected clusters.

How do I detect unauthorized mining on my Ray cluster?

Run ps aux and look for processes named kworker/0:0, dns-filter, and .python3.6. Check outbound DNS queries for pool.supportxmr.com and eu.zano.k1pool.com. Run crontab -l on all nodes and review /etc/cron.d/ for entries that pipe shell scripts from GitHub or GitLab repositories. Check GPU utilization with nvidia-smi; ShadowRay 2.0 caps GPU usage at approximately 60% to avoid detection, so sustained high-but-not-100% utilization with no legitimate job running is a strong indicator. Review Ray cluster job history via the dashboard for jobs you did not submit.

What is the CISA August 20 deadline for CVE-2025-62593?

CISA added CVE-2025-62593 to the Known Exploited Vulnerabilities catalog on August 18, 2026, and set a mandatory remediation deadline of August 20, 2026 for Federal Civilian Executive Branch agencies under Binding Operational Directive 22-01. The two-day window reflects confirmed in-the-wild exploitation and the severity of the RCE capability. Non-federal organizations are not legally bound by CISA deadlines but should treat the August 20 date as an operational urgency signal: the 48-hour federal window indicates assessed risk of significant exploitation in the immediate term.

What data can attackers steal from a compromised Ray cluster?

Attackers with access to a compromised Ray cluster can exfiltrate anything present in the cluster environment. Oligo documented one case where 240 gigabytes of compressed data was accessible, including source code, AI model weights and checkpoints, training datasets, and database credentials. Ray clusters routinely hold AWS IAM credentials in environment variables for cloud storage access, application database passwords, and proprietary model weights representing months of GPU training time. The ShadowRay 2.0 campaign also accessed MySQL databases and AWS EKS role credentials from compromised clusters.

Sources & references

  1. CISA, Adds One Known Exploited Vulnerability to Catalog (CVE-2025-62593), August 17 2026
  2. The Hacker News, CISA Flags Actively Exploited Ray Flaw That Can Trigger Browser-Based RCE
  3. Oligo Security, ShadowRay 2.0: Attackers Turn AI Against Itself in Global Campaign
  4. Security Affairs, U.S. CISA adds Ray-Project Ray flaw to Known Exploited Vulnerabilities catalog
  5. GitHub, Ray 2.52.0 Release Notes

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