Buffer overflow in Zyxel VMG4005-B50B firmware
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
A buffer overflow vulnerability in the UPnP DeletePortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Zyxel VMG4005-B50B firmware — zyxel.com/global/en/support/security-advisories/zyxel-secur…
2 records Highest priority Priority LOW 2 LOW
Other records, highest priority first
- TI-2026-03350 Buffer overflow in Zyxel VMG4005-B50B firmwarePriority LOW 28
Timeline
- 2026-10-02 Threatist record created from CVE-2026-3871
- 2026-10-03 Alias added: GHSA-c8pm-7pr3-cmh3
More Zyxel vulnerabilities
- TI-2023-16198 Buffer overflow in Zyxel ATP series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2023-16197 Buffer overflow in Zyxel ATP series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2023-13281 OS command injection in Zyxel ZyWALL/USG series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2023-12582 OS command injection in Zyxel NAS326 firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2022-12682 OS command injection in Zyxel USG FLEX 100 firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2020-17772 Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-3871 · CVE Program
- CVE-2026-3871 · NVD
- FIRST EPSS
- GHSA-c8pm-7pr3-cmh3 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences