Meta React Server Components Remote Code Execution Vulnerability (CVE-2025-55182)
Severity: critical · Patch status: patched · Since 2025-12-05 · CVE-2025-55182
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. CISA added CVE-2025-55182 to its Known Exploited Vulnerabilities catalog on Dec 5, 2025, which means attackers are exploiting it in the wild. CISA reports known use in ransomware campaigns.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Dec 12, 2025 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch