CVE-2026-44291
Description
A flaw was found in protobufjs, a library that compiles protobuf definitions into JavaScript functions. This prototype pollution vulnerability occurs when Object.prototype is polluted, allowing attacker-controlled properties to be resolved as valid protobuf type information. This can lead to attacker-controlled strings being emitted into generated JavaScript code, potentially resulting in arbitrary code execution.
Statement
This Important flaw in protobufjs, a JavaScript library, potentially enables arbitrary code execution when a separate prototype pollution vulnerability is present in an application. Exploitation requires an attacker to first pollute Object.prototype and then trigger protobufjs functionality that generates encode or decode code for affected types. Red Hat products utilizing protobufjs may be impacted if they are vulnerable to prototype pollution.
Mitigation
Mitigation involves preventing prototype pollution within applications that utilize protobufjs. Administrators should ensure that untrusted input cannot pollute `Object.prototype` in the application or its dependencies. Additionally, isolating schema and message processing from untrusted application states can prevent attacker-controlled properties from being resolved as valid protobuf type information.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Injected code can access resources that the attacker is directly prevented from accessing.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. As a result, code injection can often result in the execution of arbitrary code. Code injection attacks can also lead to loss of data integrity in nearly all cases, since the control-plane data injected is always incidental to data recall or writing.
Non-Repudiation
Technical Impact: Hide Activities
Often the actions performed by injected control code are unlogged.
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