Meta React Server Components Remote Code Execution Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2025-12-05
• Known to be used in ransomware campaigns
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 10.0

[ Description ]Official description

A pre-authentication remote code execution vulnerability exists in React Server Components versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0 including the following packages: react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack. The vulnerable code unsafely deserializes payloads from HTTP requests to Server Function endpoints.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 12 Dec 2025): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

• Patch on react.devVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
• Patch on openwall.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• react.dev/blog/2025/12/03/critical-security-vulnerability-in-react-server-componentsPatchVendor Advisory
• www.facebook.com/security/advisories/cve-2025-55182Vendor Advisory
• www.openwall.com/lists/oss-security/2025/12/03/4Mailing ListPatchThird Party Advisory
• news.ycombinator.com/itemIssue Tracking
• aws.amazon.com/blogs/security/china-nexus-cyber-threat-groups-rapidly-exploit-react2she…Third Party Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource