Vulnerability
CVE-2025-55182
Meta React and React Server Components: unauthenticated remote code execution
Most severe levelDEFCON 3 · Substantial risk
Official data
- CVSS 3.1
- 10.0 · critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-502
- EPSS
- 99.73% probability of exploitation in the next 30 days, higher than 99% of CVEs
- CISA KEV catalogue
- Yes, since 5 December 2025 · used in ransomware campaigns
Sources: NVD (CVSS, weakness, publication), FIRST (EPSS), CISA (KEV catalogue).
Data read on 5 November 2026.
Timeline
- 3 December 2025Published on NVD
- 4 December 2025First in the DefenceLevel briefing
- 5 December 2025Added to the CISA KEV catalogue
In DefenceLevel briefings7 days
- 10 April 2026New in the last 24 hoursDEFCON 4
- 3 April 2026Worth watching
- 10 January 2026Worth watching
- 8 December 2025Still ongoingDEFCON 4
- 7 December 2025Still ongoingDEFCON 4
- 6 December 2025New in the last 24 hoursDEFCON 3
- 4 December 2025New in the last 24 hoursDEFCON 4
Last 12 months.
The full analysis is in the briefingThe full analysis is in your archive
Why it matters now, who is affected and what to do: every day at 05:00 UTC, for subscribers.Why it matters, who is affected and what to do, as in the daily briefing.