CVE-2026-45740: protobufjs Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-jggg-4jg4-v7c6
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CVSS 5.3
CWE-674
Published
Advisory Summary

CVE-2026-45740 is a MODERATE (CVSS 5.3) denial of service vulnerability (CWE-674: Uncontrolled Recursion) affecting protobufjs libraries in the npm ecosystem. The issue involves denial of service via unbounded recursive json descriptor expansion. Remediation is available by upgrading affected packages to version 7.5.8, 8.2.0.

CVE-2026-45740 at a Glance

CVE Identifier CVE-2026-45740
GHSA Identifier GHSA-jggg-4jg4-v7c6
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-674: Uncontrolled Recursion
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-2026-45740

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: 7.5.8 
npm install protobufjs@7.5.8
protobufjs fixed: 8.2.0 
npm install protobufjs@8.2.0
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-2026-45740, 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 7.5.8), 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-674: Uncontrolled Recursion, where the product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. 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 could recurse without a depth limit while expanding nested JSON descriptors through `Root.fromJSON()` and `Namespace.addJSON()`. A crafted JSON descriptor with deeply nested namespace definitions could cause the JavaScript call stack to be exhausted during descriptor loading. ## Impact An attacker who can provide JSON descriptors loaded by an application may be able to crash the process or otherwise cause schema loading to fail with a stack overflow. This affects applications that load JSON descriptors from untrusted sources with affected versions. ## Preconditions - The application must load JSON descriptor data influenced by an attacker. - The crafted descriptor must contain deeply nested `nested` namespace objects. - The affected `Root.fromJSON()` / `Namespace.addJSON()` descriptor expansion path must process the crafted input. ## Workarounds Avoid loading untrusted protobuf JSON descriptors with affected versions. If immediate upgrade is not possible, reject excessively nested descriptor structures at an outer validation boundary where feasible, or isolate descriptor loading in a process that can be safely restarted.

CVE-2026-45740 Affected protobufjs Versions

2 component(s)
Fixed Versions:
7.5.88.2.0
Product / Package Ecosystem Affected Versions Fixed Version
protobufjs
npm/protobufjs
npm
< 7.5.8
7.5.8
protobufjs
npm/protobufjs
npm
≥ 8.0.0
< 8.2.0
8.2.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jggg-4jg4-v7c6
NVD — CVE-2026-45740 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45740
protobufjs Source Repository REPOSITORY
https://github.com/protobufjs/protobuf.js

Frequently Asked Questions

What is CVE-2026-45740?
CVE-2026-45740 is a security vulnerability in protobufjs involving Denial of Service via unbounded recursive JSON descriptor expansion under CWE-674: Uncontrolled Recursion.
Which protobufjs versions are affected?
Affected versions include releases prior to 7.5.8, 8.2.0 across affected packages: protobufjs.
What version fixes CVE-2026-45740?
Upgrading to 7.5.8, 8.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is protobufjs affected?
Yes, protobufjs is affected in releases prior to 7.5.8, 8.2.0. Upgrade your dependency to 7.5.8, 8.2.0 or later.
What is the CVSS score of CVE-2026-45740?
CVE-2026-45740 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-2026-45740?
CVE-2026-45740 is classified under CWE-674: Uncontrolled Recursion (The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.).
How can I check npm dependencies for CVE-2026-45740?
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-jggg-4jg4-v7c6",
  "modified" : "2026-05-19T16:21:34Z",
  "published" : "2026-05-19T16:21:33Z",
  "aliases" : [ "CVE-2026-45740" ],
  "summary" : "protobufjs: Denial of Service via unbounded recursive JSON descriptor expansion",
  "details" : "## Summary\n\nprotobufjs could recurse without a depth limit while expanding nested JSON descriptors through `Root.fromJSON()` and `Namespace.addJSON()`.\n\nA crafted JSON descriptor with deeply nested namespace definitions could cause the JavaScript call stack to be exhausted during descriptor loading.\n\n## Impact\n\nAn attacker who can provide JSON descriptors loaded by an application may be able to crash the process or otherwise cause schema loading to fail with a stack overflow.\n\nThis affects applications that load JSON descriptors from untrusted sources with affected versions.\n\n## Preconditions\n\n- The application must load JSON descriptor data influenced by an attacker.\n- The crafted descriptor must contain deeply nested `nested` namespace objects.\n- The affected `Root.fromJSON()` / `Namespace.addJSON()` descriptor expansion path must process the crafted input.\n\n## Workarounds\n\nAvoid loading untrusted protobuf JSON descriptors with affected versions. If immediate upgrade is not possible, reject excessively nested descriptor structures at an outer validation boundary where feasible, or isolate descriptor loading in a process that can be safely restarted.",
  "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" : "7.5.8"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.5.7"
    }
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "protobufjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jggg-4jg4-v7c6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45740"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/protobufjs/protobuf.js"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-674" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-19T16:21:33Z",
    "nvd_published_at" : "2026-05-13T16:17:00Z"
  }
}