CVE-2025-66478

unknownknown exploitedcovered by 1 sourcefirst seen 2026-06-05

Actively exploited. CVE-2025-66478 is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.

Bulletin ID: AWS-2025-030 Scope: AWS Content Type: Important (requires attention) Publication Date: 2025/12/03 20:00 PM PST Description: AWS is aware of the recently disclosed CVE-2025-55182 which affects the React Server Flight protocol in React versions 19.0, 19.1, and 19.2, as well as in Next.js versions 15.x, 16.x, Next.js 14.3.0-canary.77 and later canary releases when using App Router. This issue may permit unauthorized remote code execution on affected applications servers. AWS is aware of CVE-2025-66478, which has been rejected as a duplicate of CVE-2025-55182. Customers using managed AWS services are not affected, and no action is required. Customers running an affected version of React or Next.js in their own environments should update to the latest patched versions immediately: - Customers using React 19.x, with Server Functions and RSC Components should update to the latest patched versions 19.0.1, 19.1.2, and 19.2.1 - Customers using Next.js 15-16 with App Router should update to a patched version

CSIRTS triage

vendor: AWS product: React Remote code executionaffected: 19.0, 19.1, 19.2; Next.js 15.x, 16.x, 14.3.0-canary.77 and later

What: An issue may permit unauthorized remote code execution on affected application servers.
Who is affected: Customers running affected versions of React or Next.js in their own environments.
Urgency: Remediation is urgent due to the potential for exploitation.
Action: Update to the latest patched versions immediately.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now.

Advisory coverage (1)

unknownexploitedCVE-2025-66478: RCE in React Server Componentsaws · 2026-06-05

External references

NVD record for CVE-2025-66478

CVE.org record

CISA KEV catalog

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