GHSA-h27x-g6w4-24gq

Next.js: Unbounded postponed resume buffering can lead to DoS

At a glance

Published
Updated
CVE
CVE-2026-27979
CVSS_V4
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

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.

Affected packages

PackageVersions
npm · nextintroduced 16.0.1, fixed 16.1.7

References

Sources

SourceLicence
OSV.devCC-BY 4.0 — GitHub Advisory Database