CVE-2026-119051

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 v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/hughsk/flat
https://github.com/hughsk/flat/blob/1d68e1d06c0210cff31e5c61ac177f3e2d3fa564/index.js#L137-L142
https://github.com/hughsk/flat/blob/1d68e1d06c0210cff31e5c61ac177f3e2d3fa564/index.js#L65-L75
https://github.com/hughsk/flat/issues/195
https://www.vulncheck.com/advisories/flat-through-6.0.1-denial-of-service-via-unflatten-numeric-array-index-keys

Configurations

No configuration.

History

29 Oct 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-29 14:17

Updated : 2026-10-29 16:21

NVD link : CVE-2026-119051

Mitre link : CVE-2026-119051

CVE.ORG link : CVE-2026-119051

JSON object : View

Products Affected

No product.

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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