GitHub Advisoryadvisory · npm

GHSA-h27x-g6w4-24gq Next.js: Unbounded postponed resume buffering can lead to DoS

MEDIUM Published 2026-03-17 Modified 2026-03-19 Official page ↗
Aliases
CVE-2026-27979
Ecosystem
npm
Packages
next
Severity
Moderate
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Weaknesses
CWE-770
Reviewed
2026-03-17

Affected packages

• npm next: >= 16.0.1, < 16.1.7 → fixed in 16.1.7

Description

Summary A request containing the `next-resume: 1` header (corresponding with a PPR resume request) would buffer request bodies without consistently enforcing `maxPostponedStateSize` in certain setups. The previous mitigation protected minimal-mode deployments, but equivalent non-minimal deployments remained vulnerable to the same unbounded postponed resume-body buffering behavior. Impact In applications using the App Router with Partial Prerendering capability enabled (via `experimental.ppr` or `cacheComponents`), an attacker could send oversized `next-resume` POST payloads that were buffered without consistent size enforcement in non-minimal deployments, causing excessive memory usage and potential denial of service. Patches Fixed by enforcing size limits across all postponed-body buffering paths and erroring when limits are exceeded. Workarounds If upgrade is not immediately possible: • Block requests containing the `next-resume` header, as this is never valid to be sent from an untrusted client.

Related

Alias · CVE (1)

  • CVE-2026-27979 Next.js is a React framework for building full-stack web applications. vulnerability

Weakness · CWE (1)

  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References