CVE-2026-71429

stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.5.0, the path filters pick, ignore, filter, and replace in src/core/filters/filter-base.js recompute the full path string from the nesting stack for every checkable token. Because the stack length equals the current nesting depth and a checkable token is emitted at every level, a depth D document costs O(D²) rather than O(D) to process. The issue is triggered by nesting depth rather than byte volume, including the documented pick({filter: 'data'}) traversal-until-match path, so an application that sends untrusted JSON through a string or RegExp filter can block the Node.js event loop and cause denial of service with a small deeply nested document. The streamArray, streamObject, and streamValues streamers are not affected because they use the constant-time asm.depth getter. This issue is fixed in version 3.5.0.

Scoring

Severity
MEDIUM
CVSS base score
6.2
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS probability
0.11%
CWE
CWE-407
Published
2026-09-03
Last modified
2026-09-04

Affected products

Weakness type

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