# CVE-2026-4621: Hidden Functionality vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to enable telnet via network.

Source: https://junglewise.ai/threats/cve-2026-4621-hidden-functionality-vulnerability-in-nec-platforms-ltd-aterm  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-27  
License: CC BY 4.0 with a link back

CVE-2026-4621 · Severity: medium · CVSS 5.6 · Published 2026-03-27

Hidden Functionality vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to enable telnet via network.

Technologies: [Nec Aterm Wf1200cr](https://junglewise.ai/threats/technologies/aterm-wf1200cr), [Nec Aterm Wf1200cr Firmware](https://junglewise.ai/threats/technologies/aterm-wf1200cr-firmware), [Nec Aterm Wg1200cr](https://junglewise.ai/threats/technologies/aterm-wg1200cr), [Nec Aterm Wg1200cr Firmware](https://junglewise.ai/threats/technologies/aterm-wg1200cr-firmware), [Nec Aterm Wg2600hm4](https://junglewise.ai/threats/technologies/aterm-wg2600hm4), [Nec Aterm Wg2600hm4 Firmware](https://junglewise.ai/threats/technologies/aterm-wg2600hm4-firmware), [Nec Aterm Wg2600hp4](https://junglewise.ai/threats/technologies/aterm-wg2600hp4), [Nec Aterm Wg2600hp4 Firmware](https://junglewise.ai/threats/technologies/aterm-wg2600hp4-firmware), [Nec Aterm Wg2600hs](https://junglewise.ai/threats/technologies/aterm-wg2600hs), [Nec Aterm Wg2600hs Firmware](https://junglewise.ai/threats/technologies/aterm-wg2600hs-firmware), [Nec Aterm Wg2600hs2](https://junglewise.ai/threats/technologies/aterm-wg2600hs2), [Nec Aterm Wg2600hs2 Firmware](https://junglewise.ai/threats/technologies/aterm-wg2600hs2-firmware), [Nec Aterm Wx1500hp](https://junglewise.ai/threats/technologies/aterm-wx1500hp), [Nec Aterm Wx1500hp Firmware](https://junglewise.ai/threats/technologies/aterm-wx1500hp-firmware), [Nec Aterm Wx3000hp](https://junglewise.ai/threats/technologies/aterm-wx3000hp), [Nec Aterm Wx3000hp Firmware](https://junglewise.ai/threats/technologies/aterm-wx3000hp-firmware), [Nec Aterm Wx3600hp](https://junglewise.ai/threats/technologies/aterm-wx3600hp), [Nec Aterm Wx3600hp Firmware](https://junglewise.ai/threats/technologies/aterm-wx3600hp-firmware). Vendors: [Nec](https://junglewise.ai/threats/vendors/nec).

## Quick answers

**Is CVE-2026-4621 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-4621 being exploited in the wild.

**How severe is CVE-2026-4621?** Medium severity, with a CVSS score of 5.6, published 27 March 2026.

**Which products and versions are affected?** Nec Aterm W1200ex-Ms, Nec Aterm W1200ex-Ms Firmware, Nec Aterm Wf1200cr, Nec Aterm Wf1200cr Firmware and 38 more. The advisory does not name versions.

**Is there a fix for CVE-2026-4621?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-4621?** Check whether you run Nec Aterm W1200ex-Ms, Nec Aterm W1200ex-Ms Firmware, Nec Aterm Wf1200cr or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Nec Aterm W1200ex-Ms
- Nec Aterm W1200ex-Ms Firmware
- Nec Aterm Wf1200cr
- Nec Aterm Wf1200cr Firmware
- Nec Aterm Wg1200cr
- Nec Aterm Wg1200cr Firmware
- Nec Aterm Wg1200hp2
- Nec Aterm Wg1200hp2 Firmware
- Nec Aterm Wg1200hp3
- Nec Aterm Wg1200hp3 Firmware
- Nec Aterm Wg1200hp4
- Nec Aterm Wg1200hp4 Firmware
- Nec Aterm Wg1200hs2
- Nec Aterm Wg1200hs2 Firmware
- Nec Aterm Wg1200hs3
- Nec Aterm Wg1200hs3 Firmware
- Nec Aterm Wg1200hs4
- Nec Aterm Wg1200hs4 Firmware
- Nec Aterm Wg1800hp3
- Nec Aterm Wg1800hp3 Firmware
- Nec Aterm Wg1800hp4
- Nec Aterm Wg1800hp4 Firmware
- Nec Aterm Wg1900hp
- Nec Aterm Wg1900hp Firmware
- Nec Aterm Wg1900hp2
- Nec Aterm Wg1900hp2 Firmware
- Nec Aterm Wg2600hm4
- Nec Aterm Wg2600hm4 Firmware
- Nec Aterm Wg2600hp4
- Nec Aterm Wg2600hp4 Firmware
- Nec Aterm Wg2600hs
- Nec Aterm Wg2600hs Firmware
- Nec Aterm Wg2600hs2
- Nec Aterm Wg2600hs2 Firmware
- Nec Aterm Wx1500hp
- Nec Aterm Wx1500hp Firmware
- Nec Aterm Wx3000hp
- Nec Aterm Wx3000hp Firmware
- Nec Aterm Wx3000hp2
- Nec Aterm Wx3000hp2 Firmware
- Nec Aterm Wx3600hp
- Nec Aterm Wx3600hp Firmware

## Related threats

- [OS Command Injection vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to execute arbitrary OS commands via network.](https://junglewise.ai/threats/cve-2026-4622-os-command-injection-vulnerability-in-nec-platforms-ltd-aterm)
- [OS Command Injection vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to execute arbitrary OS commands via network.](https://junglewise.ai/threats/cve-2026-4620-os-command-injection-vulnerability-in-nec-platforms-ltd-aterm)
- [Path Traversal vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to wtite over any file via network.](https://junglewise.ai/threats/cve-2026-4619-path-traversal-vulnerability-in-nec-platforms-ltd-aterm-series)
- [Missing Authorization vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to get a specific device…](https://junglewise.ai/threats/cve-2026-4309-missing-authorization-vulnerability-in-nec-platforms-ltd-aterm)