CVE-2026-104183
Description
A flaw was found in stream-json. When parsing JSON data, the Assembler component directly assigns properties, allowing an input key named 'proto' to replace a parsed object's internal prototype rather than creating a standard property. An attacker who supplies crafted input can exploit this behavior to inject unexpected properties into parsed objects, potentially causing incorrect application decisions or service disruption.
Statement
This vulnerability is rated as Moderate impact because exploitation requires processing untrusted input and manipulation is restricted to individual parsed object instances rather than causing global prototype pollution. In Red Hat desktop tooling where this library is bundled as a dependency, an attacker would need to supply a crafted JSON file directly to the application, limiting the blast radius to the client session. Because the issue does not permit arbitrary code execution or elevate privileges on the underlying operating system, the overall risk to Red Hat environments remains Moderate.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.1 | N/A | 5.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
An attacker could modify sensitive data or program variables.
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Other,Integrity
Technical Impact: Varies by Context; Alter Execution Logic
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