Vulnerability-Lookup

GHSA-VP52-PCJ8-J9QC

Vulnerability from github – Published: 2026-09-01 21:32 – Updated: 2026-09-01 21:32

Summary

gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation

Details

Impact

An unauthenticated remote attacker can initiate a gRPC stream and purposefully fragment their payload into millions of tiny (e.g., 1-byte) HTTP/2 DATA frames. Even if the total payload volume falls within the configured connection and stream flow-control windows, each independent fragment incurs memory overhead due to internal tracking structures and queue allocation.

Repeated fragmentation massively inflates the heap space consumed by the stream. An attacker multiplexing multiple concurrent streams can exhaust the memory bounds of the runtime, forcing a runtime panic or OutOfMemory condition and leading to a remote Denial of Service (DoS).

Patches

The change to fix this issue is merged in master and a patch release, 1.83.1, has been published that contains this fix.

Workarounds

This vulnerability is mitigated by implementing receive buffer compaction. Consecutive small data buffers are automatically coalesced into larger buffers from a shared pool once the overhead is perceived to be excessive relative to actual payload data, drastically minimizing per-frame memory overheads.

This behavior is enabled by default. A temporary escape hatch is provided via the environment variable GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION=false to disable the feature if unforeseen issues arise, but it will be removed in a future release.

Severity

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.83.0"
      },
      "package": {
        "ecosystem": "Go",
        "name": "google.golang.org/grpc"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.83.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-84304"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-01T21:32:41Z",
    "nvd_published_at": "2026-09-01T19:17:30Z",
    "severity": "HIGH"
  },
  "details": "### Impact\nAn unauthenticated remote attacker can initiate a gRPC stream and purposefully fragment their payload into millions of tiny (e.g., 1-byte) HTTP/2 DATA frames. Even if the total payload volume falls within the configured connection and stream flow-control windows, each independent fragment incurs memory overhead due to internal tracking structures and queue allocation.\n\nRepeated fragmentation massively inflates the heap space consumed by the stream. An attacker multiplexing multiple concurrent streams can exhaust the memory bounds of the runtime, forcing a runtime panic or OutOfMemory condition and leading to a remote Denial of Service (DoS).\n\n### Patches\nThe change to fix this issue is merged in `master` and a patch release, 1.83.1, has been published that contains this fix.\n\n### Workarounds\nThis vulnerability is mitigated by implementing receive buffer compaction. Consecutive small data buffers are automatically coalesced into larger buffers from a shared pool once the overhead is perceived to be excessive relative to actual payload data, drastically minimizing per-frame memory overheads.\n\nThis behavior is enabled by default. A temporary escape hatch is provided via the environment variable `GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION=false` to disable the feature if unforeseen issues arise, but it will be removed in a future release.",
  "id": "GHSA-vp52-pcj8-j9qc",
  "modified": "2026-09-01T21:32:41Z",
  "published": "2026-09-01T21:32:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/security/advisories/GHSA-vp52-pcj8-j9qc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-84304"
    },
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/pull/9331"
    },
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/pull/9333"
    },
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/commit/7354d9c8debb4bcf2225bf429857078de310c176"
    },
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/commit/8cfeca0e1ee5ea0980dcc320e20240fa1079ec77"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/grpc/grpc-go"
    },
    {
      "type": "WEB",
      "url": "https://github.com/grpc/grpc-go/releases/tag/v1.83.1"
    }
  ],
  "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:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation"
}

CVE-2026-84304 (GCVE-0-2026-84304)

Vulnerability from cvelistv5 – Published: 2026-09-01 18:19 – Updated: 2026-09-01 19:24

Title

gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation

Summary

gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, internal/transport/transport.go stores each fragmented HTTP/2 DATA frame as a separate recvMsg in recvBuffer, so millions of one-byte frames can consume disproportionate heap memory even when payload bytes remain within connection and stream flow-control windows. An unauthenticated remote attacker can use concurrent multiplexed streams to exhaust process memory and cause a runtime panic or out-of-memory termination. Receive-buffer compaction is enabled by default and can be controlled temporarily with GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION. This issue is fixed in version 1.83.1.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-01 19:23 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M mitre root

References

6 references

URL	Tags
https://github.com/grpc/grpc-go/security/advisori…	x_refsource_CONFIRM
https://github.com/grpc/grpc-go/pull/9331	x_refsource_MISC
https://github.com/grpc/grpc-go/pull/9333	x_refsource_MISC
https://github.com/grpc/grpc-go/commit/7354d9c8de…	x_refsource_MISC
https://github.com/grpc/grpc-go/commit/8cfeca0e1e…	x_refsource_MISC
https://github.com/grpc/grpc-go/releases/tag/v1.83.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
grpc	grpc-go	Affected: < 1.83.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-84304",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-01T19:23:26.130673Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-01T19:24:36.867Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "grpc-go",
          "vendor": "grpc",
          "versions": [
            {
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            }
          ]
        }
      ],
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        {
          "lang": "en",
          "value": "gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, internal/transport/transport.go stores each fragmented HTTP/2 DATA frame as a separate recvMsg in recvBuffer, so millions of one-byte frames can consume disproportionate heap memory even when payload bytes remain within connection and stream flow-control windows. An unauthenticated remote attacker can use concurrent multiplexed streams to exhaust process memory and cause a runtime panic or out-of-memory termination. Receive-buffer compaction is enabled by default and can be controlled temporarily with GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION. This issue is fixed in version 1.83.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "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:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
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      ],
      "problemTypes": [
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          "descriptions": [
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              "cweId": "CWE-400",
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              "lang": "en",
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        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/grpc/grpc-go/security/advisories/GHSA-vp52-pcj8-j9qc",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/grpc/grpc-go/security/advisories/GHSA-vp52-pcj8-j9qc"
        },
        {
          "name": "https://github.com/grpc/grpc-go/pull/9331",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/grpc/grpc-go/pull/9331"
        },
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          "name": "https://github.com/grpc/grpc-go/pull/9333",
          "tags": [
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          "url": "https://github.com/grpc/grpc-go/pull/9333"
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          "tags": [
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        },
        {
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          "url": "https://github.com/grpc/grpc-go/releases/tag/v1.83.1"
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      "source": {
        "advisory": "GHSA-vp52-pcj8-j9qc",
        "discovery": "UNKNOWN"
      },
      "title": "gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation"
    }
  },
  "cveMetadata": {
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    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-84304",
    "datePublished": "2026-09-01T18:19:10.100Z",
    "dateReserved": "2026-09-01T16:17:43.078Z",
    "dateUpdated": "2026-09-01T19:24:36.867Z",
    "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.

Detection rules are retrieved from Rulezet.

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.