In all versions of Node.js 10 prior to 10.9.0, an argument processing flaw can cause `Buffer.alloc()` to return uninitialized memory.

Published 8 y ago 2018-08-21 · modified 29 d ago 2026-10-08 · JSON

CVSS

7.5

v3.1 · NVD

CISA KEV

not known exploited

EPSS

3.3%

percentile 89%

Public exploits

none known

In all versions of Node.js 10 prior to 10.9.0, an argument processing flaw can cause `Buffer.alloc()` to return uninitialized memory. This method is intended to be safe and only return initialized, or cleared, memory. The third argument specifying `encoding` can be passed as a number, this is misinterpreted by `Buffer's` internal "fill" method as the `start` to a fill operation. This flaw may be abused where `Buffer.alloc()` arguments are derived from user input to return uncleared memory blocks that may contain sensitive information.

CISA SSVC assessment

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 29 d ago 2026-10-08

Exploit prediction (EPSS)

3.29% probability of exploitation in the next 30 days, higher than 89% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
NVD	3.1	7.5	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
NVD	2.0	5.0	`AV:N/AC:L/Au:N/C:P/I:N/A:N`

Affected products

The Node.js Project Node.js

Classification

Weakness

CWE-226 Sensitive Information in Resource Not Removed Before Reuse
CWE-908 Use of Uninitialized Resource

Technology feeds

Node.js (RSS, critical only)

References

access.redhat.com /errata/RHSA-2018:2553 · vendor-advisory, x_refsource_REDHAT, x_transferred
nodejs.org /en/blog/vulnerability/august-2018-security-releases/ · x_refsource_CONFIRM, x_transferred

Sources

CVE List: CVE-2018-7166
NVD: CVE-2018-7166

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.

Summary