CVE-2023-35138

Name: CVE-2023-35138
Creator: NVD / NIST
Published: 2023-11-30T02:15:42.737+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 40.00%

Last modified Jun 17, 2026

CVE-2023-35138 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A command injection vulnerability in the “show_zysync_server_contents” function 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 HTTP POST request.. EPSS estimates a 40.00% chance of exploitation in the next 30 days.

Description

A command injection vulnerability in the “show_zysync_server_contents” function 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 HTTP POST request.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

40.00%

98.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zyxel	Nas326 Firmware	<= 5.21\(aazf.14\)c0
Zyxel	Nas542 Firmware	<= 5.21\(abag.11\)c0

References

Timeline

Published: Nov 30, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-35138?

How severe is CVE-2023-35138?

CVE-2023-35138 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 40.00% probability of exploitation in the next 30 days.

How do I fix CVE-2023-35138?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-35138?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST