CVE-2026-119051

Medium

Description

flat through 6.0.1 contains an uncontrolled resource allocation vulnerability in unflatten() that allows attackers to create huge sparse arrays via unbounded numeric keys. Attackers can supply flattened keys such as a.4294967294, causing iteration with forEach, spread or JSON.stringify to block the Node.js event loop.

SeverityMedium
CVSS5.9
Exploit probability—
ProductHughsk Flat
PublishedOct 29, 2026
First seenNov 4, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
hughsk flatv ≤ 6.0.1—

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