CVE-2026-44291 HIGH

CVE-2026-44291: protobufjs: Code generation gadget after prototype pollution

Vendor Protobufjs
Product protobuf.js
Weakness CWE-94 · Code injection
Published May 13, 2026
Last update May 13, 2026

CVSS base score

8.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs used plain objects with inherited prototypes for internal type lookup tables used by generated encode and decode functions. If Object.prototype had already been polluted, those lookup tables could resolve attacker-controlled inherited properties as valid protobuf type information. This could cause attacker-controlled strings to be emitted into generated JavaScript code. This vulnerability is fixed in 7.5.6 and 8.0.2.

Key dates

02Disclosure timeline

May 13, 2026 CVE published
May 13, 2026 Record updated