CVE-2026-44907 in react-server-dom-webpack
Summary
by MITRE • 07/21/2026
A denial of service vulnerability could be triggered by sending specially crafted HTTP requests to server function endpoints, this could lead to excessive CPU usage; affecting the following packages: react-server-dom-webpack, react-server-dom-parcel, react-server-dom-turbopack (versions 19.0.0 through 19.0.7, 19.1.0 through 19.1.8, and 19.2.0 through 19.2.7).
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Analysis
by VulDB Data Team • 07/21/2026
This vulnerability represents a critical denial of service condition that can be exploited through carefully crafted HTTP requests targeting server function endpoints within React Server Components implementations. The flaw manifests when the affected packages process malformed or specially constructed requests that cause the server to consume excessive CPU resources during request handling. This occurs because the vulnerable code paths fail to properly validate input parameters or implement adequate rate limiting mechanisms, allowing attackers to craft requests that trigger inefficient processing loops or recursive operations within the server-side rendering pipeline.
The technical implementation of this vulnerability stems from insufficient input sanitization and validation within the React Server Components runtime environments. When these packages receive HTTP requests containing malformed data structures or unexpected parameter combinations, they execute processing logic that consumes disproportionate computational resources relative to the request complexity. This behavior aligns with CWE-400 weakness classification related to uncontrolled resource consumption, where the system fails to properly limit resource usage during request processing. The affected versions span multiple build toolchains including webpack parcel and turbopack, indicating a systemic issue within the React Server Components architecture rather than isolated component failures.
The operational impact of this vulnerability extends beyond simple service disruption as it can effectively render entire server instances unavailable to legitimate users while consuming substantial computational resources. Attackers can leverage this weakness to perform resource exhaustion attacks that may require significant system restarts or manual intervention to resolve. The affected packages react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack all share common processing logic that makes them equally susceptible to this attack vector. This vulnerability particularly affects web applications that rely heavily on React Server Components for server-side rendering and data fetching operations, potentially compromising availability of critical business applications.
Mitigation strategies should focus on implementing comprehensive input validation at multiple layers of the application architecture including HTTP request parsing, parameter validation, and resource usage monitoring. Organizations should upgrade to patched versions of the affected packages as soon as possible, with particular attention to version ranges 19.0.0 through 19.0.7, 19.1.0 through 19.1.8, and 19.2.0 through 19.2.7. Network-level protections such as rate limiting and request size restrictions can provide additional defense-in-depth measures while implementing proper logging and monitoring to detect anomalous CPU usage patterns. The ATT&CK framework categorizes this vulnerability under T1499.004 Disruption of Service, where adversaries leverage resource exhaustion techniques to compromise system availability. Security teams should also consider implementing automated response mechanisms that can detect and block suspicious request patterns before they consume excessive system resources.