CVE-2026-119051
mediumflat through 6.0.1 contains an uncontrolled resource allocation vulnerability in unflatten() that allows attackers to create huge sparse arrays via unbounded n…
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.
CVSS
5.9
5.9 (CVSS v3.1)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)
Timeline (UTC)
Published: 2026-10-29 14:17
Modified: 2026-10-29 16:21
NVD status: Deferred
Last synced 15 hours ago
Verified against the source API 2026-10-29 16:44 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/hughsk/flat disclosure@vulncheck.com
- https://github.com/hughsk/flat/blob/1d68e1d06c0210cff31e5c61ac177f3e2d3fa564/index.js#L137... disclosure@vulncheck.com
- https://github.com/hughsk/flat/blob/1d68e1d06c0210cff31e5c61ac177f3e2d3fa564/index.js#L65-... disclosure@vulncheck.com
- https://github.com/hughsk/flat/issues/195 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/flat-through-6.0.1-denial-of-service-via-unflatten-nu... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-29 16:44 UTC · record ↗