CVE-2026-41242

CRITICAL

protobufjs Type Fields - Arbitrary Code Execution

Title source: manual
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-41242. PoCs published by Giangdurian, 4chech.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-41242, a critical code injection vulnerability in protobuf.js (≤8.0.0/≤7.5.4) where malicious type names in protobuf schemas are improperly handled during dynamic code generation, leading to arbitrary JavaScript execution in Node.js environments.

Description

protobufjs compiles protobuf definitions into JavaScript (JS) functions. In versions prior to 8.0.1 and 7.5.5, attackers can inject arbitrary code in the "type" fields of protobuf definitions, which will then execute during object decoding using that definition. Versions 8.0.1 and 7.5.5 patch the issue.

Exploits (2)

github WORKING POC
by Giangdurian · pythonpoc
https://github.com/Giangdurian/CVE-2026-41242

This repository contains a functional exploit for CVE-2026-41242, a critical code injection vulnerability in protobuf.js (≤8.0.0/≤7.5.4) where malicious type names in protobuf schemas are improperly handled during dynamic code generation, leading to arbitrary JavaScript execution in Node.js environments.

Classification
Working Poc 99%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: protobuf.js (versions ≤8.0.0 and ≤7.5.4), @protobufjs/codegen ≤2.0.4
No auth needed
Prerequisites: Target application must load protobuf schemas from untrusted sources at runtime · Target must be running a vulnerable version of protobuf.js or @protobufjs/codegen · Node.js environment (for RCE; code injection may work in browser contexts)
mistral-large-3 · analyzed Aug 07, 2026 Full analysis →
github STUB
by 4chech · javascriptpoc
https://github.com/4chech/CVE-2026-41242

The repository contains only node_modules dependencies (protobufjs libraries) with no actual exploit code or technical details related to CVE-2026-41242. No PoC, scanner, or writeup is present.

Classification
Stub 95%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: unknown
No auth needed
mistral-large-3 · analyzed Apr 26, 2026 Full analysis →

Scores

CVSS v3 9.8
EPSS 0.0075
EPSS Percentile 51.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact total

Details

CWE
CWE-94
Status published
Products (5)
npm/protobufjs 8.0.0 - 8.0.1npm
protobufjs/protobuf.js < 7.5.5
protobufjs/protobuf.js >= 8.0.0-experimental, < 8.0.1
protobufjs_project/protobufjs 8.0.0
protobufjs_project/protobufjs < 7.5.5
Published Apr 18, 2026
Tracked Since Apr 18, 2026