# CVE-2026-27979: Next.js: Unbounded postponed resume buffering can lead to DoS

> CVE-2026-27979: Next.js: Unbounded postponed resume buffering can lead to DoS. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-27979
Last updated: 2026-06-17T10:28:00Z

- Published: 2026-03-18 00:13 UTC · Updated: 2026-06-17 10:28 UTC · Assigner: GitHub\_M
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.69%, 53th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-770

## Description

Next.js is a React framework for building full-stack web applications. Starting in version 16.0.1 and prior to version 16.1.7, 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. 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. This is fixed in version 16.1.7 by enforcing size limits across all postponed-body buffering paths and erroring when limits are exceeded. If upgrading is not immediately possible, block requests containing the \`next-resume\` header, as this is never valid to be sent from an untrusted client.

## Affected vendors and products

- vercel: next.js

## Tracked companies

- [Vercel](https://rewindex.com/company/vercel.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-27979)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-27979)
- [https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1](https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1)
- [https://github.com/vercel/next.js/releases/tag/v16.1.7](https://github.com/vercel/next.js/releases/tag/v16.1.7)
- [https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq](https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-27979 · Markdown: https://rewindex.com/cve/CVE-2026-27979.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-27979 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:10:04.061Z