# GHSA-8h8q-6873-q5fj: Next.js Vulnerable to Denial of Service with Server Components

> Attackers can cause denial of service via excessive CPU usage by sending crafted requests to Next.js App Router Server Function endpoints.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 May 2026

## What is GHSA-8h8q-6873-q5fj?

GHSA-8h8q-6873-q5fj is a denial of service vulnerability in next, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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](https://github.com/facebook/react/security/advisories/GHSA-rv78-f8rc-xrxh). 

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.

## Which versions are affected by GHSA-8h8q-6873-q5fj?

4 open source packages ship an affected version, including next.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `next` | npm | From 13.0.0 | 15.5.16 |
| `next` | npm | From 13.0.0 | 15.5.16 |
| `next` | npm | From 16.0.0 | 16.2.5 |
| `next` | npm | From 16.0.0 | 16.2.5 |

## How do I fix GHSA-8h8q-6873-q5fj?

Upgrade next to a fixed version for your release line: 15.5.16 or 16.2.5.

## Is GHSA-8h8q-6873-q5fj being exploited?

There is no known exploitation of GHSA-8h8q-6873-q5fj in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-8h8q-6873-q5fj and fix it if it is affected.

What it is: GHSA-8h8q-6873-q5fj is a denial of service vulnerability in next, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-8h8q-6873-q5fj in the wild and no public exploit code.

Affected packages and fixed versions:
- next (npm): affected from 13.0.0; fixed in 15.5.16
- next (npm): affected from 13.0.0; fixed in 15.5.16
- next (npm): affected from 16.0.0; fixed in 16.2.5
- next (npm): affected from 16.0.0; fixed in 16.2.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-8h8q-6873-q5fj/ (Markdown: https://insights.sbomify.com/GHSA-8h8q-6873-q5fj/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-8h8q-6873-q5fj

---
From sbomify Insights: https://insights.sbomify.com/GHSA-8h8q-6873-q5fj/
Summaries are generated and may contain mistakes; the official description above is the record.