Vulnerability-Lookup

GHSA-H27X-G6W4-24GQ

Vulnerability from github – Published: 2026-03-17 16:16 – Updated: 2026-03-19 18:31

Summary

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

Details

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.

Severity

6.9 (Medium)


                  
                    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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "next"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "16.0.1"
            },
            {
              "fixed": "16.1.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27979"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-17T16:16:49Z",
    "nvd_published_at": "2026-03-18T01:16:04Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\nA 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.\n\n## Impact\nIn 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.\n\n## Patches\nFixed by enforcing size limits across all postponed-body buffering paths and erroring when limits are exceeded.  \n\n## Workarounds\nIf upgrade is not immediately possible:\n- Block requests containing the `next-resume` header, as this is never valid to be sent from an untrusted client.",
  "id": "GHSA-h27x-g6w4-24gq",
  "modified": "2026-03-19T18:31:02Z",
  "published": "2026-03-17T16:16:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27979"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vercel/next.js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/releases/tag/v16.1.7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Next.js: Unbounded postponed resume buffering can lead to DoS"
}

CVE-2026-27979 (GCVE-0-2026-27979)

Vulnerability from cvelistv5 – Published: 2026-03-18 00:13 – Updated: 2026-03-18 19:51

Title

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

Summary

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.

Severity

6.9 (Medium)


                        
                          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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-18 19:51 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7606 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/vercel/next.js/security/adviso…	x_refsource_CONFIRM
https://github.com/vercel/next.js/commit/c885d482…	x_refsource_MISC
https://github.com/vercel/next.js/releases/tag/v16.1.7	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
vercel	next.js	Affected: >= 16.0.1, < 16.1.7

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-27979",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-18T19:51:23.444351Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-18T19:51:36.190Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "next.js",
          "vendor": "vercel",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 16.0.1, \u003c 16.1.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-18T00:13:29.748Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq"
        },
        {
          "name": "https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1"
        },
        {
          "name": "https://github.com/vercel/next.js/releases/tag/v16.1.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/vercel/next.js/releases/tag/v16.1.7"
        }
      ],
      "source": {
        "advisory": "GHSA-h27x-g6w4-24gq",
        "discovery": "UNKNOWN"
      },
      "title": "Next.js: Unbounded postponed resume buffering can lead to DoS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27979",
    "datePublished": "2026-03-18T00:13:29.748Z",
    "dateReserved": "2026-02-25T03:24:57.793Z",
    "dateUpdated": "2026-03-18T19:51:36.190Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-H27X-G6W4-24GQ

Summary

Impact

Patches

Workarounds

CVE-2026-27979 (GCVE-0-2026-27979)

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour