CVE-2018-7166: In all versions of Node.js 10 prior to 10.9.0, an argument processing flaw can cause `Buffer.alloc()` to retur

This month

HIGH 7.5REMOTEUPGRADE

CVE-2018-7166 is a high-severity flaw (CVSS 7.5) affecting node.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.3% (top 12%)
CISA exploited list	No
Weakness	CWE-226, CWE-908
Published	2018-08-21
Last modified	2026-10-08

Publisher (CNA): Node.js · Vendor: nodejs

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-08-21 12:29 UTCPublished CVE record published
2026-10-08 22:16 UTCUpdated Record last modified

nodejs node.js UPGRADE

Affected: >= 10.0.0 and < 10.9.0

Fixed in: 10.9.0

Safe to downgrade to: a release before 10.0.0

1. Check installed version

apt-cache policy node.js || rpm -q node.js || node.js --version

2. UPGRADE to 10.9.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade node.js

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade node.js

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 10.0.0 (Debian / Ubuntu)

apt-cache madison node.js sudo apt install node.js=<VERSION_BEFORE_10.0.0> sudo apt-mark hold node.js

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list node.js sudo dnf downgrade node.js-<VERSION_BEFORE_10.0.0> sudo dnf versionlock add node.js

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-7166?

node.js: upgrade to 10.9.0. Exact commands for each OS are on this page.

Is CVE-2018-7166 being exploited?

CVE-2018-7166 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-7166 affect?

CVE-2018-7166 affects node.js. Severity is high (CVSS 7.5). 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 spe

How urgent is CVE-2018-7166?

Priority 53/100. High severity; Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities

Related CVEs

CVE-2026-111497 CRITICAL 9.8 EXPLOITED UPGRADE UPGRADE Google Brotli Unchecked Return Value Vulnerability
CVE-2026-48617 HIGH 8.2 UPGRADE A flaw in Node.js Permission Model enforcement allows Bypass via `process.report.writeReport()` Path Misvalida
CVE-2026-48937 HIGH 7.5 UPGRADE A flaw in Node.js HTTP/2 server API can cause servers to keep accepting data even after sending a `GOAWAY` fra
CVE-2026-48931 LOW 3.7 DOWNGRADE A flaw in Node.js HTTP Agent can cause a client to accept as valid a response that is send before the client h
CVE-2026-48933 HIGH 7.5 DOWNGRADE A flaw in Node.js WebCrypto implementation can crash the process if the input of `subtle.encrypt()` is a multi

References

← Back to latest CVEs