Known exploited · Meta
CVE-2025-55182: Meta React Server Components Remote Code Execution Vulnerability
What it is
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.
- Vendor
- Meta
- Product
- React Server Components
- Added to KEV
- December 5, 2025
- CISA due date
- December 12, 2025
- Ransomware use
- Known
- Weakness
- Not mapped by CISA
What CISA requires
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of React Server Components you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before December 12, 2025 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
Not sure you are clear?
We check where you run it, patch or mitigate with your team, and look for signs it was already used against you.
Talk to our teamT Academy
Train the engineers who fix it
Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.
Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.