What is CVE-2023-22923?

CVE-2023-22923 is a medium-severity vulnerability in Zyxel Nbg-418n, classified under Use of Externally-Controlled Format String. CVSS score: 6.5/10. Published 2023-05-01.

How severe is CVE-2023-22923?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Zyxel Nbg-418n

CVE-2023-22923

A format string vulnerability in a binary of the Zyxel NBG-418N v2 firmware versions prior to V1.00(AARP.14)C0 could allow a remote authenticated attacker to cause denial-of-service (DoS) conditions on an affected device.

Published 2023-05-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Zyxel Nbg-418n — versions v2
Zyxel Nbg-418n Firmware
Zyxel Nbg-418n V2 Firmware — versions < V1.00(AARP.14)C0

Weakness classification (CWE)

CWE-134 — Use of Externally-Controlled Format String

References

www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for… (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-22923?: CVE-2023-22923 is a medium-severity vulnerability in Zyxel Nbg-418n, classified under Use of Externally-Controlled Format String. CVSS score: 6.5/10. Published 2023-05-01.
How severe is CVE-2023-22923?: Medium severity. CVSS v3 base score is 6.5 out of 10.