stream-json: Prototype pollution: Assembler writes this.current[this.key] on plain objects
stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the inherited setter and causes parsed object prototype replacement instead of creating an own data property. Applications that make authorization or feature decisions from inherited values can therefore consume attacker-controlled properties, and a null prototype can disrupt code that expects Object.prototype methods. The researcher treats parsing untrusted JSON as part of the project contract, while the maintainer states that documented inputs are locally owned dumps, exports, or logs and characterizes the attack vector as local. The global Object.prototype is not polluted. This issue is fixed in version 3.6.0.
CVE-2026-104183
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-104183
stream-json
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "uhop",
"product": "stream-json",
"versions": [
{
"status": "affected",
"version": "< 3.6.0"
}
]
}
]- Related CVEs
- CVE-2026-104183
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #7784 · Revision 1
- Added to Heist Feed
- Publisher date