stream-json: pick/ignore/filter/replace filters are O(depth²) on nested input — small crafted JSON blocks the event loop for seconds→minutes (DoS)

published 2026-09-03 2 mo ago modified 2026-09-10 1 mo ago also GHSA-528h-pc64-c93x , EUVD-2026-70733

cvss: 6.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 1

npm stream-json 3.5.0

github.com/uhop/stream-json@a869fb9 commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-71429 updated 2026-10-16 cvss 6.2

stream-json: stream-json: Denial of Service due to inefficient processing of deeply nested JSON

Red Hat Build of Podman Desktop rh-podman-desktop.git 1.1.0
affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-09-04)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/uhop/stream-json/security/advisories/GHSA-528h-pc64-c93x referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.2	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	6.2	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	stream-json	<3.5.0	3.5.0

Affected products

uhop stream-json

Classification

Weakness

CWE-407 Inefficient Algorithmic Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary