Vulnerabilities in pkg:npm/socket.io-parser

PACKAGE
Advisory Identifier: GHSA-2m8v-j782-fhvr
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Advisory Summary

CVE-2026-69185 is a HIGH (CVSS 7.5) zero-attachment memory exhaustion vulnerability (CWE-20: Improper Input Validation) affecting Socket.io parser libraries in the npm ecosystem. The issue involves zero-attachment memory exhaustion. Remediation is available by upgrading affected packages to version 4.2.7, 3.4.5, 3.3.6.

5 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:npm/socket.io-parser

5 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:npm/socket.io-parser. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-2m8v-j782-fhvr CVE-2026-69185 HIGH Socket.IO: Zero-attachment Memory Exhaustion
GHSA-677m-j7p3-52f9 CVE-2026-33151 HIGH socket.io allows an unbounded number of binary attachments
GHSA-cqmj-92xf-r6r9 CVE-2023-32695 MODERATE Insufficient validation when decoding a Socket.IO packet
GHSA-qm95-pgcg-qqfq CVE-2022-2421 CRITICAL Insufficient validation when decoding a Socket.IO packet
GHSA-xfhh-g9f5-x4m4 CVE-2020-36049 HIGH Resource exhaustion in socket.io-parser

CVE-2026-69185 at a Glance

CVE Identifier CVE-2026-69185
GHSA Identifier GHSA-2m8v-j782-fhvr
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-20: Improper Input Validation
Affected Product Socket.io parser
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-69185

To remediate this vulnerability, upgrade all affected Socket.io parser dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

socket.io-parser fixed: 4.2.7 
npm install socket.io-parser@4.2.7
socket.io-parser fixed: 3.4.5 
npm install socket.io-parser@3.4.5
socket.io-parser fixed: 3.3.6 
npm install socket.io-parser@3.3.6
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls socket.io-parser

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-69185, inspect your project dependencies using npm:

npm ls socket.io-parser

Analyze the terminal output to locate any version of Socket.io parser in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.7), your application is affected.

Note: The npm ls socket.io-parser command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Socket.io parser, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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 <4.2.7` | `socket.io@4.x` and `socket.io-client@4.x` | `4.2.7` | | `>=3.4.0 <3.4.5` | `socket.io@2.x` | `3.4.5` | | `<3.3.6` | `socket.io-client@2.x` | `3.3.6` | ### 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](https://github.com/socketio/socket.io/discussions)

CVE-2026-69185 Affected Socket.io parser Versions

3 component(s)
Fixed Versions:
4.2.73.4.53.3.6
Product / Package Ecosystem Affected Versions Fixed Version
socket.io-parser
npm/socket.io-parser
npm
≥ 4.0.0
< 4.2.7
4.2.7
socket.io-parser
npm/socket.io-parser
npm
≥ 3.4.0
< 3.4.5
3.4.5
socket.io-parser
npm/socket.io-parser
npm
< 3.3.6
3.3.6

References

GitHub Advisory / Wiki ADVISORY
https://github.com/socketio/socket.io/security/advisories/GHSA-2m8v-j782-fhvr
Security Fix Commit FIX COMMIT
https://github.com/socketio/socket.io/commit/7c6ef571a00656718e9e05e3b948fd1758b2a7b4
Security Fix Commit FIX COMMIT
https://github.com/socketio/socket.io/commit/9c6323e5cde41bd75df3379b5fc9293664a5f240
Security Fix Commit FIX COMMIT
https://github.com/socketio/socket.io/commit/ced94ffa3ac020a8f3c14eb98a3bf34acb14d291
Socket.io parser Source Repository REPOSITORY
https://github.com/socketio/socket.io

Frequently Asked Questions

What is CVE-2026-69185?
CVE-2026-69185 is a security vulnerability in Socket.io parser involving Zero-attachment Memory Exhaustion under CWE-20: Improper Input Validation.
Which Socket.io parser versions are affected?
Affected versions include releases prior to 4.2.7, 3.4.5, 3.3.6 across affected packages: socket.io-parser.
What version fixes CVE-2026-69185?
Upgrading to 4.2.7, 3.4.5, 3.3.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is socket.io-parser affected?
Yes, socket.io-parser is affected in releases prior to 4.2.7, 3.4.5, 3.3.6. Upgrade your dependency to 4.2.7, 3.4.5, 3.3.6 or later.
What is the CVSS score of CVE-2026-69185?
CVE-2026-69185 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-69185?
CVE-2026-69185 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check npm dependencies for CVE-2026-69185?
Run the dependency tree command: 'npm ls socket.io-parser'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2m8v-j782-fhvr",
  "modified" : "2026-08-03T19:09:44Z",
  "published" : "2026-08-03T19:09:44Z",
  "aliases" : [ "CVE-2026-69185" ],
  "summary" : "Socket.IO: Zero-attachment Memory Exhaustion",
  "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| `>=4.0.0 <4.2.7` | `socket.io@4.x` and `socket.io-client@4.x` | `4.2.7`       |\n| `>=3.4.0 <3.4.5` | `socket.io@2.x`                            | `3.4.5`       |\n| `<3.3.6`         | `socket.io-client@2.x`                     | `3.3.6`       |\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)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "socket.io-parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.2.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "socket.io-parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.4.0"
      }, {
        "fixed" : "3.4.5"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "socket.io-parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.3.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/socketio/socket.io/security/advisories/GHSA-2m8v-j782-fhvr"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/socketio/socket.io/commit/7c6ef571a00656718e9e05e3b948fd1758b2a7b4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/socketio/socket.io/commit/9c6323e5cde41bd75df3379b5fc9293664a5f240"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/socketio/socket.io/commit/ced94ffa3ac020a8f3c14eb98a3bf34acb14d291"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/socketio/socket.io"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-754" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-03T19:09:44Z",
    "nvd_published_at" : null
  }
}