PT-2026-21621 · Zyxel · Zyxel Wx3100-T0+1

Published 2026-02-24 · Updated 2026-02-24 · CVE-2025-11845

Positive Technologies (AI Summary)

CVSS v3.1

4.9

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.6)C0 Zyxel WX3100-T0 firmware versions through 5.50(ABVL.4.8)C0

Description A flaw exists in the certificate downloader CGI program that could allow a denial-of-service (DoS) condition. An authenticated attacker with administrator privileges can trigger this by sending a specially crafted HTTP request. The issue is due to a null pointer dereference.

Recommendations Update Zyxel VMG3625-T50B firmware to a version later than 5.50(ABPM.9.6)C0. Update Zyxel WX3100-T0 firmware to a version later than 5.50(ABVL.4.8)C0.

Fix

DoS

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2025-11845

Affected Products

Zyxel Vmg3625-T50B

Zyxel Wx3100-T0

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2025-11845 · Security Note
• https://zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-null-pointer-dereference-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-02-24-2026 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-11845 · Vendor Advisory
• https://t.me/cveNotify/152953 · Telegram Post
• https://twitter.com/CVEnew/status/2026184635093577740 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2026174331470946523 · Twitter Post