Deserialization in Meta React-Server-Dom-Parcel

CVE-2026-23869

A denial of service vulnerability exists in React Server Components, affecting the following packages: react-server-dom-parcel, react-server-dom-turbopack and react-server-dom-webpack (versions 19.0.0 through 19.0.4, 19.1.0 through 19.1.5, and 19.2.0 through 19.2.4). The vulnerability is triggered by sending specially crafted HTTP requests to Server Function endpoints.The payload of the HTTP request causes excessive CPU usage for up to a minute ending in a thrown error that is catchable.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23869: held from 0.016 to 0.016.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-23869?
CVE-2026-23869 is a high-severity vulnerability in Meta React-Server-Dom-Parcel, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-04-08.
How severe is CVE-2026-23869?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2026-23869 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.