CVE-2025-62593: Ray-Project Ray Code Injection Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Ray-Project Ray. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-08-17, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-08-20; treat that as the outer limit, not the target.
• EPSS 62.5%, percentile 99: FIRST’s model estimates a 62.5% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Only applies if your dependency tree includes ray (PyPI) < 2.52.0, fixed in 2.52.0. Check your lockfile, including transitive dependencies.
• Editorial verdict: Patch this week. Ray CVE-2025-62593: Browser-Driven RCE Against Ray Devs — Upgrade Ray to 2.52.0 or later on developer machines and internal clusters this week; the attack needs a Firefox or Safari user to load a hostile page while a pre-2.52 dashboard is running, and the public evidence of real-world use is thin.

What it is

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.

From the GitHub advisory

Summary

Developers working with Ray as a development tool can be exploited via a critical RCE vulnerability exploitable via Firefox and Safari.

Due to the longstanding decision by the Ray Development team to not implement any sort of authentication on critical endpoints, like the /api/jobs & /api/jobagent/jobs/ has once again led to a severe vulnerability that allows attackers to execute arbitrary code against Ray. This time in a development context via the browsers 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).

CISA’s summary

Ray-Project Ray contains a code injection vulnerability that could allow remote code execution. Developers using Ray as a development tool may be exposed to this vulnerability exploitable through Firefox and Safari.

Weakness type: CWE-94, CWE-352.

Product: Ray-Project Ray · Assigned by: GitHub_M · Published: 2025-11-26

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: passive

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-08-17; federal due date 2026-08-20. Known ransomware use: Unknown.
• CISA 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 SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 62.46% probability of exploitation activity in the next 30 days; percentile 99.

Timeline

• 2025-11-26 — CVE record published by GitHub_M
• 2025-11-26 — GitHub-reviewed advisory GHSA-q279-jhrf-cc6v published (critical)
• 2025-11-26 — erroneo.us brief: Ray CVE-2025-62593: Browser-Driven RCE Against Ray Devs
• 2026-08-17 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-08-20 — CISA remediation deadline for US federal agencies
• 2026-10-01 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (github.com) github.com
2. Listed in CISA KEV notes (github.com) github.com

Vulnerability records

1. GitHub Advisory GHSA-q279-jhrf-cc6v github.com
2. CVE.org record CVE-2025-62593 cve.org
3. NVD entry CVE-2025-62593 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

Other references from the CVE record and advisory

1. bitsight.com bitsight.com
2. github.com github.com
3. docs.ray.io docs.ray.io
4. en.wikipedia.org en.wikipedia.org
5. github.com github.com
6. github.com github.com

All exploited Ray-Project vulnerabilities · Critical PyPI advisories · Today’s Security Digest