GitHub Advisoryadvisory · npm
GHSA-h27x-g6w4-24gq Next.js: Unbounded postponed resume buffering can lead to DoS
MEDIUM
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
- https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq web
- https://nvd.nist.gov/vuln/detail/CVE-2026-27979 advisory
- https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1 web
- https://github.com/vercel/next.js package
- https://github.com/vercel/next.js/releases/tag/v16.1.7 web