Risk Letters

Exploited vulnerability

CVE-2025-55182

TLP:CLEAR

Meta React Server Components Remote Code Execution Vulnerability

Meta React Server Components contains a remote code execution vulnerability that could allow unauthenticated remote code execution by exploiting a flaw in how React decodes payloads sent to React Server Function endpoints. Please note CVE-2025-66478 has been rejected, but it is associated with CVE-2025- 55182.

Facts

  • Vendor: Meta
  • Product: React Server Components
  • CVSS: 10
  • EPSS (probability of exploitation within 30 days): 99.8 %
  • On CISA's Known Exploited Vulnerabilities list since: 5 December 2025
  • First known exploitation: 5 December 2025
  • Used in ransomware campaigns (per CISA): Yes
  • CISA's deadline for US federal agencies: 12 December 2025
  • First seen by Risk Letters: 5 December 2025

Members see which Nordic sectors the flaw hits, and what to do about it.

Get the full brief

Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD