CVE-2021-23386

Remote Memory Exposure

7.7 HighFix available

This affects the package dns-packet before 5.2.2. It creates buffers with allocUnsafe and does not always fill them before forming network packets. This can expose internal application memory over unencrypted network when querying crafted invalid domain names.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: Low
Availability: Low

Exploit likelihood

1.43%Up 0.4 points since May 21, 2021

What each source reports

CVE List Score used 7.7

Remote Memory Exposure

Record: CVE-2021-23386
CVSS 3.1: 7.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Updated: 2026-11-02

EUVDEUVD-2021-0923 7.7

Record: EUVD-2021-0923
CVSS 3.1: 7.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Updated: 2026-11-03

GitHub AdvisoriesGHSA-3wcq-x3mq-6r9p 7.7

Potential memory exposure in dns-packet

This affects the package dns-packet before versions 1.3.2 and 5.2.2. It creates buffers with allocUnsafe and does not always fill them before forming network packets. This can expose internal application memory over unencrypted network when querying crafted invalid domain names.

Record: GHSA-3wcq-x3mq-6r9p
CVSS 3.1: 7.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-200, CWE-908
Updated: 2026-11-02

NVD 7.7

Record: CVE-2021-23386
CVSS 3.1: 7.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0: 4.0 MediumAV:N/AC:L/Au:S/C:P/I:N/A:N
Weakness: CWE-909
Updated: 2026-11-02

OSV 6.5

Record: CVE-2021-23386
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVGHSA-3wcq-x3mq-6r9p 7.7

Potential memory exposure in dns-packet

Record: GHSA-3wcq-x3mq-6r9p
CVSS 3.1: 7.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-200, CWE-908
Updated: 2026-11-02

OSVCLSA-2026-1780447839 No score

TuxCare security update for dns-packet (1 CVE)

TuxCare rebuilt dns-packet to address 1 CVE. Fixed in 1.3.1-tuxcare.1.

Record: CLSA-2026-1780447839
Updated: 2026-11-02

OSVROOT-APP-NPM-CVE-2021-23386 No score

CVE-2021-23386 in dns-packet - Patched by Root

Root has patched CVE-2021-23386 in the dns-packet package for Root:npm. Multiple fixed versions available.

Record: ROOT-APP-NPM-CVE-2021-23386
Updated: 2026-11-02

Affected products

dns-packet project dns-packet

Affected packages

Affected packages
Package	Affected	Fixed
`dns-packet` npm	before 1.3.2	1.3.2
`dns-packet` npm	2.0.0 up to 5.2.2	5.2.2
`dns-packet` TuxCare:npm	1.3.1-tuxcare.0 up to 1.3.1-tuxcare.1, plus listed versions 1.3.1	1.3.1-tuxcare.1
`dns-packet` Root:npm	before 1.3.1-aikido.1	1.3.1-aikido.1
`@rootio/dns-packet` Root:npm	before 1.3.1-root.io.1	1.3.1-root.io.1

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-23386 is a high vulnerability (CVSS 7.7) in Dns-packet Project Dns-packet, published May 20, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.43%, the 73rd percentile. Fixed in dns-packet 1.3.2.