CVE-2026-23869
HighCVSS 7.5Exploitation Probability (EPSS)
Elevated risk73th percentile - higher than 73% of all known CVEs
Summary
A denial of service vulnerability in React Server Components (react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack) versions 19.0.0-19.0.4, 19.1.0-19.1.5, and 19.2.0-19.2.4. Specially crafted HTTP requests to Server Function endpoints cause excessive CPU usage for about a minute, ending in a catchable error.
Risk Assessment
An attacker can overload the server, causing temporary application unavailability. Although the error is catchable, a high volume of such requests can lead to significant resource exhaustion.
Recommendation
Immediately update affected packages to versions 19.0.5, 19.1.6, or 19.2.5 (or later). As a temporary mitigation, restrict access to Server Function endpoints or deploy WAF rules to block suspicious requests.
Other vulnerabilities in React Server Components
See all- CVE-2025-67779High
Vulnerability in React Server Components versions 19.0.2, 19.1.3 and 19.2.2 is an incomplete fix for CVE-2025-55184 and still allows unsafe deserialization of payloads from HTTP requests to Server Function endpoints, causing an infinite loop that hangs the server process.
- CVE-2025-55184High
Pre-authentication denial of service vulnerability in React Server Components versions 19.0.0, 19.0.1, 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1, including react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack, allows unsafe deserialization of payloads from HTTP requests to Server Function endpoints, causing an infinite loop that hangs the server process.
- CVE-2025-55183Medium
An information leak vulnerability exists in specific configurations of React Server Components versions 19.0.0, 19.0.1, 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1, including the packages react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack. A specifically crafted HTTP request sent to a vulnerable Server Function may unsafely return the source code of any Server Function.
- CVE-2025-55182CriticalActively exploited
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 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.
- CVE-2026-23864High
Multiple denial of service vulnerabilities have been found in React Server Components packages (react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack). Specially crafted HTTP requests to Server Function endpoints can cause server crashes, out-of-memory exceptions, or excessive CPU usage.
Original NVD description (English source)
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 data from NVD (NIST) · CISA KEV · EPSS