React Server Components RCE exploited in Japan
A deserialization flaw in React Server Components (CVE-2025-55182), also affecting Next.js, is being actively exploited in Japan to achieve remote code execution.
Sourceipa.go.jp — open the original
What to check
- Applies to
- The 4 CVEs named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- CISA lists CVE-2025-55182 as exploited in the wild.
IPA Japan issued an advisory warning that React Server Components, a server-side feature of the React JavaScript library, contains a vulnerability (CVE-2025-55182) allowing deserialization of untrusted data. Successful exploitation lets a remote attacker execute arbitrary code, and the flaw also impacts other products built on the same components, notably Next.js. On December 10, IPA updated the advisory to note that attacks believed to exploit this vulnerability have already occurred domestically, and warned that exploitation activity is likely to expand.
On December 12, three additional vulnerabilities were disclosed alongside the original issue: two denial-of-service flaws (CVE-2025-55184, CVE-2025-67779) and a source code exposure vulnerability (CVE-2025-55183). IPA recommends organizations address all four issues together and apply the patched versions released by the developers as soon as possible.
Given the confirmed in-the-wild exploitation of a remote code execution flaw in a widely deployed web framework component, organizations running React Server Components or Next.js should prioritize patching immediately. No specific indicators of compromise or attacker attribution have been publicly disclosed at this time.
Mentioned in this report
Source reporting: https://www.ipa.go.jp/security/security-alert/2025/alert20251209.html
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