Event-loop blocking via quadratic path reconstruction
Published Sep 3, 2026 · Updated Sep 4, 2026
Algorithmic-complexity denial of service in stream-json before 3.5.0 allows attackers to block a Node.js event loop with nested JSON. The pick, ignore, filter, and replace path filters repeatedly join the full nesting stack for each checkable token, producing quadratic work as depth grows. Reachability requires a consuming application to pass untrusted input through a string or RegExp path filter; the result is CPU-bound service interruption.
Summary
What happened
Algorithmic-complexity denial of service in stream-json before 3.5.0 allows attackers to block a Node.js event loop with nested JSON. The pick, ignore, filter, and replace path filters repeatedly join the full nesting stack for each checkable token, producing quadratic work as depth grows. Reachability requires a consuming application to pass untrusted input through a string or RegExp path filter; the result is CPU-bound service interruption.
The record
- CVE
- CVE-2026-71429
- Published
- Sep 3, 2026
- Updated
- Sep 4, 2026
- Vendor
- uhop
- Product
- stream-json
- Classifications
- CWE-407, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 3, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.5.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-528h-pc64-c93x nested-JSON proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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