CVE-2026-44294: Protobufjs Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-2pr8-phx7-x9h3
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CVSS 5.3
CWE-20
Published
Advisory Summary

CVE-2026-44294 is a MODERATE (CVSS 5.3) denial of service vulnerability (CWE-20: Improper Input Validation) affecting Protobufjs libraries in the npm ecosystem. The issue involves denial of service from crafted field names in generated code. Remediation is available by upgrading affected packages to version 7.5.6, 8.0.2.

CVE-2026-44294 at a Glance

CVE Identifier CVE-2026-44294
GHSA Identifier GHSA-2pr8-phx7-x9h3
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-20: Improper Input Validation
Affected Product Protobufjs
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

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:L).

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 Low (A:L)

How to Fix CVE-2026-44294

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

protobufjs fixed: 7.5.6 
npm install protobufjs@7.5.6
protobufjs fixed: 8.0.2 
npm install protobufjs@8.0.2
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 protobufjs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-44294, inspect your project dependencies using npm:

npm ls protobufjs

Analyze the terminal output to locate any version of Protobufjs in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.5.6), your application is affected.

Note: The npm ls protobufjs 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 Protobufjs, 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

## Summary protobufjs generated JavaScript property accessors from schema-controlled field and oneof names. Certain control characters in field names were not escaped before being embedded into generated function bodies. A crafted schema or JSON descriptor could therefore cause generated encode, decode, verify, or conversion functions to fail during compilation. ## Impact An attacker who can provide or influence a protobuf schema or JSON descriptor may be able to make affected message types unusable by causing protobufjs runtime code generation to throw a syntax error. This is a denial of service issue for applications that load untrusted schemas or descriptors. Applications that only use trusted, application-defined schemas are not directly affected by this issue. The issue is not known to allow code execution by itself. ## Preconditions - The application must allow an attacker to control or influence a protobuf schema or JSON descriptor. - The crafted input must define a field name containing control characters that reach generated JavaScript property access. - The application must perform an operation that triggers protobufjs code generation for the affected type, such as encode, decode, verify, `fromObject`, or `toObject`. ## Workarounds Do not load protobuf schemas or JSON descriptors from untrusted sources with affected versions. If untrusted schemas must be accepted, validate field names before loading them and reject names containing control characters.

CVE-2026-44294 Affected Protobufjs Versions

2 component(s)
Fixed Versions:
7.5.68.0.2
Product / Package Ecosystem Affected Versions Fixed Version
protobufjs
npm/protobufjs
npm
< 7.5.6
7.5.6
protobufjs
npm/protobufjs
npm
≥ 8.0.0
< 8.0.2
8.0.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-2pr8-phx7-x9h3
NVD — CVE-2026-44294 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44294
Protobufjs Source Repository REPOSITORY
https://github.com/protobufjs/protobuf.js
Protobufjs Release RELEASE
https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v7.5.6
Protobufjs Release RELEASE
https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.0.2

Frequently Asked Questions

What is CVE-2026-44294?
CVE-2026-44294 is a security vulnerability in Protobufjs involving Denial of service from crafted field names in generated code under CWE-20: Improper Input Validation.
Which Protobufjs versions are affected?
Affected versions include releases prior to 7.5.6, 8.0.2 across affected packages: protobufjs.
What version fixes CVE-2026-44294?
Upgrading to 7.5.6, 8.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is protobufjs affected?
Yes, protobufjs is affected in releases prior to 7.5.6, 8.0.2. Upgrade your dependency to 7.5.6, 8.0.2 or later.
What is the CVSS score of CVE-2026-44294?
CVE-2026-44294 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-44294?
CVE-2026-44294 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-2026-44294?
Run the dependency tree command: 'npm ls protobufjs'. 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-2pr8-phx7-x9h3",
  "modified" : "2026-05-14T20:35:22Z",
  "published" : "2026-05-12T15:06:17Z",
  "aliases" : [ "CVE-2026-44294" ],
  "summary" : "protobuf.js: Denial of service from crafted field names in generated code",
  "details" : "## Summary\n\nprotobufjs generated JavaScript property accessors from schema-controlled field and oneof names. Certain control characters in field names were not escaped before being embedded into generated function bodies. A crafted schema or JSON descriptor could therefore cause generated encode, decode, verify, or conversion functions to fail during compilation.\n\n## Impact\n\nAn attacker who can provide or influence a protobuf schema or JSON descriptor may be able to make affected message types unusable by causing protobufjs runtime code generation to throw a syntax error.\n\nThis is a denial of service issue for applications that load untrusted schemas or descriptors. Applications that only use trusted, application-defined schemas are not directly affected by this issue.\n\nThe issue is not known to allow code execution by itself.\n\n## Preconditions\n\n- The application must allow an attacker to control or influence a protobuf schema or JSON descriptor.\n- The crafted input must define a field name containing control characters that reach generated JavaScript property access.\n- The application must perform an operation that triggers protobufjs code generation for the affected type, such as encode, decode, verify, `fromObject`, or `toObject`.\n\n## Workarounds\n\nDo not load protobuf schemas or JSON descriptors from untrusted sources with affected versions. If untrusted schemas must be accepted, validate field names before loading them and reject names containing control characters.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "protobufjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.5.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.5.5"
    }
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "protobufjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 8.0.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-2pr8-phx7-x9h3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44294"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/protobufjs/protobuf.js"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v7.5.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.0.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-12T15:06:17Z",
    "nvd_published_at" : "2026-05-13T16:16:56Z"
  }
}