Zyxel fixes 1 critical vulnerability

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[TLP:CLEAR] Zyxel fixes 1 critical vulnerability

Zyxel fixes a critical vulnerability in the firmware of some CPE models. The affected models and the corresponding fixed firmware versions can be found at [1].

Zyxel EMG, EX, VMG, XMG firmware - RCE, DoS (CVE-2025-7673)

CVSS 9.8 (Critical)

An unauthenticated remote attacker is, due to a buffer overflow vulnerability in the URL parser of the zhttpd web server on some CPE models, allowed, by sending a specially crafted HTTP request, to cause a denial of service and potentially achieve remote code execution [1][2].

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

More information:

CVE-2025-7673 at cve.org, NVD
CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') at cwe.mitre.org

The vulnerability was publicly disclosed 16. 7. 2025.

Links

By CESNET, z.s.p.o. Michaela Jarošová on 16. 7. 2025.

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[TLP:CLEAR] Zyxel fixes 1 critical vulnerability

Zyxel EMG, EX, VMG, XMG firmware - RCE, DoS (CVE-2025-7673)

CVSS 9.8 (Critical)

Links