Summary
A vulnerability affects certain React Server Components packages for versions 19.x and frameworks that use the affected packages, including Next.js 13.x, 14.x, 15.x, and 16.x using the App Router. The issue is tracked upstream as CVE-2026-23870.
A specially crafted HTTP request can be sent to any App Router Server Function endpoint that, when deserialized, may trigger excessive CPU usage. This can result in denial of service in unpatched environments.
Impact
The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.
GHSA-8H8Q-6873-Q5FJ has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (15.5.16, 16.2.5); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
next to 15.5.16 or later; next to 16.2.5 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-8H8Q-6873-Q5FJ? GHSA-8H8Q-6873-Q5FJ is a high-severity allocation of resources without limits or throttling vulnerability in next (npm), affecting versions >= 13.0.0, < 15.5.16. It is fixed in 15.5.16, 16.2.5. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
- How severe is GHSA-8H8Q-6873-Q5FJ? GHSA-8H8Q-6873-Q5FJ has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of next are affected by GHSA-8H8Q-6873-Q5FJ? next (npm) versions >= 13.0.0, < 15.5.16 is affected.
- Is there a fix for GHSA-8H8Q-6873-Q5FJ? Yes. GHSA-8H8Q-6873-Q5FJ is fixed in 15.5.16, 16.2.5. Upgrade to this version or later.
- Is GHSA-8H8Q-6873-Q5FJ exploitable, and should I be worried? Whether GHSA-8H8Q-6873-Q5FJ is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-8H8Q-6873-Q5FJ is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-8H8Q-6873-Q5FJ?
- Upgrade
nextto 15.5.16 or later - Upgrade
nextto 16.2.5 or later
- Upgrade