9.8

CVE-2023-4473: zyxel nas326_firmware OS Command Injection

CVSS: 9.8v3.1CriticalModified
Published 30-11-2023Last modified 16-12-2025
Open JSON

Vulnerability summary

CVE-2023-4473 is a critical (CVSS 9.8) OS Command Injection vulnerability in zyxel nas326_firmware. EPSS estimates a 41.35% chance of exploitation in the next 30 days, higher than 98.6% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
41.35%
0%100%
High · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 30-11-2023
    PublishedVulnerability first disclosed.
  2. 16-12-2025
    Last modifiedVulnerability information updated.

Description

A command injection vulnerability in the web server of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted URL to a vulnerable device.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

41.35%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

0.00 pp

From 41.35% on 20-09-2026

20-09-202620-10-2026
EPSS score
41.35%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Zyxel4 products

1 vendor · 4 products

References

2 links