Vulnerability-Lookup

GHSA-677M-J7P3-52F9

Vulnerability from github – Published: 2026-03-18 17:26 – Updated: 2026-03-20 21:33

Summary

socket.io allows an unbounded number of binary attachments

Details

Impact

A specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory.

Patches

Version range	Used by	Fixed version
`>=4.0.0 <4.2.6`	`socket.io@4.x` and `socket.io-client@4.x`	`4.2.6`
`>=3.4.0 <3.4.4`	`socket.io@2.x`	`3.4.4`
`<3.3.5`	`socket.io-client@2.x`	`3.3.5`

Workarounds

There is no known workaround except upgrading to a safe version.

For more information

If you have any questions or comments about this advisory:

Open a discussion here

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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "socket.io-parser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.3.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "socket.io-parser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.4.0"
            },
            {
              "fixed": "3.4.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "socket.io-parser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33151"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-754"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-18T17:26:14Z",
    "nvd_published_at": "2026-03-20T21:17:15Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nA specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory.\n\n### Patches\n\n| Version range    | Used by                                    | Fixed version |\n|------------------|--------------------------------------------|---------------|\n| `\u003e=4.0.0 \u003c4.2.6` | `socket.io@4.x` and `socket.io-client@4.x` | `4.2.6`       |\n| `\u003e=3.4.0 \u003c3.4.4` | `socket.io@2.x`                            | `3.4.4`       |\n| `\u003c3.3.5`         | `socket.io-client@2.x`                     | `3.3.5`       |\n\n### Workarounds\n\nThere is no known workaround except upgrading to a safe version.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n- Open a discussion [here](https://github.com/socketio/socket.io/discussions)",
  "id": "GHSA-677m-j7p3-52f9",
  "modified": "2026-03-20T21:33:51Z",
  "published": "2026-03-18T17:26:14Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/socketio/socket.io/security/advisories/GHSA-677m-j7p3-52f9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33151"
    },
    {
      "type": "WEB",
      "url": "https://github.com/socketio/socket.io/commit/719f9ebab0772ffb882bd614b387e585c1aa75d4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/socketio/socket.io/commit/9d39f1f080510f036782f2177fac701cc041faaf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/socketio/socket.io/commit/b25738c416c4e32fbff62ee182afa8f6d0dacf78"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/socketio/socket.io"
    }
  ],
  "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": "socket.io allows an unbounded number of binary attachments"
}

CVE-2026-33151 (GCVE-0-2026-33151)

Vulnerability from cvelistv5 – Published: 2026-03-20 20:13 – Updated: 2026-03-23 16:50

Title

socket.io allows an unbounded number of binary attachments

Summary

Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. Prior to versions 3.3.5, 3.4.4, and 4.2.6, a specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory. This issue has been patched in versions 3.3.5, 3.4.4, and 4.2.6.

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: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-23 16:50 UTC

CWE

CWE-20 - Improper Input Validation
CWE-754 - Improper Check for Unusual or Exceptional Conditions

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/socketio/socket.io/security/ad…	x_refsource_CONFIRM
https://github.com/socketio/socket.io/commit/719f…	x_refsource_MISC
https://github.com/socketio/socket.io/commit/9d39…	x_refsource_MISC
https://github.com/socketio/socket.io/commit/b257…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
socketio	socket.io	Affected: < 3.3.5 Affected: >= 3.4.0, < 3.4.4 Affected: >= 4.0.0, < 4.2.6

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-33151",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-23T16:50:08.681178Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
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    ],
    "cna": {
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          "vendor": "socketio",
          "versions": [
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              "version": "\u003c 3.3.5"
            },
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              "status": "affected",
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            },
            {
              "status": "affected",
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            }
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      "descriptions": [
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          "lang": "en",
          "value": "Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. Prior to versions 3.3.5, 3.4.4, and 4.2.6, a specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory. This issue has been patched in versions 3.3.5, 3.4.4, and 4.2.6."
        }
      ],
      "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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      ],
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          "descriptions": [
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              "lang": "en",
              "type": "CWE"
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          "descriptions": [
            {
              "cweId": "CWE-754",
              "description": "CWE-754: Improper Check for Unusual or Exceptional Conditions",
              "lang": "en",
              "type": "CWE"
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T20:13:31.424Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/socketio/socket.io/security/advisories/GHSA-677m-j7p3-52f9",
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          ],
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        },
        {
          "name": "https://github.com/socketio/socket.io/commit/719f9ebab0772ffb882bd614b387e585c1aa75d4",
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          "url": "https://github.com/socketio/socket.io/commit/b25738c416c4e32fbff62ee182afa8f6d0dacf78"
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      "source": {
        "advisory": "GHSA-677m-j7p3-52f9",
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    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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    "cveId": "CVE-2026-33151",
    "datePublished": "2026-03-20T20:13:31.424Z",
    "dateReserved": "2026-03-17T21:17:08.885Z",
    "dateUpdated": "2026-03-23T16:50:16.998Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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