Buffer overflow in VMG4005-B50B - CVE-2026-3870
Published: June 2, 2026
Vulnerability identifier: #VU133237
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-3870
CWE-ID: CWE-119
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: ZyXEL Communications Corp.
Affected software:
VMG4005-B50B
VMG4005-B50B
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error in the UPnP AddPortMapping() command. A remote attacker on the local network can trigger memory corruption and cause a denial of service condition on the target system.
How to mitigate CVE-2026-3870
Install updates from vendor's website.