Zte Mc801a Firmware 2021 May 2026

ZTE MC801A Firmware (2021): The Transition to 5G Stability

The ZTE MC801A is one of the most popular 5G CPE (Customer Premises Equipment) units, widely used by carriers like Three UK, A1, and various European ISPs. The year 2021 was a pivotal time for this device, marking the transition from early, unstable 5G implementations to mature, high-performance software.

If you are looking to downgrade, upgrade, or restore a ZTE MC801A from this era, here is everything you need to know about the 2021 firmware lifecycle. zte mc801a firmware 2021

Security Patches: The Hidden Benefit of 2021 Updates

In early 2021, security researchers discovered a vulnerability in the MC801A’s web server that allowed a remote attacker to bypass login credentials (CVE-2021-26728). If you are still running a pre-2021 firmware (B03 or older), your device is vulnerable to this exploit. ZTE MC801A Firmware (2021): The Transition to 5G

All 2021 firmware builds (B07+) contain the patch for this critical vulnerability. Updating is not just about features; it’s about preventing your 5G gateway from becoming part of a botnet. The Problem: Users with their own high-end routers

3. The "Bridge Mode Removal" Controversy (Late 2021 – Versions: B09, B12)

This is the update that made headlines on forums like Reddit and ISPReview. In an attempt to simplify support, ZTE (at the request of several carriers) removed the IP Passthrough / Bridge Mode function from many March 2021 builds onward.

• The Problem: Users with their own high-end routers (Asus, Ubiquiti, etc.) could no longer avoid Double NAT.
• The Workaround: Users stuck on 2021 firmware had to use DMZ or port forwarding, which was not a true replacement.
• Outcome: This created a schism in the community. Users either blocked updates or sought downgrade methods.

6. Recommendations for Users Stuck on 2021 Firmware (Historical)

1. Upgrade to 2022 or later firmware (e.g., B12, B15) if available via carrier OTA.
2. Disable IPv6 in LAN settings to reduce disconnections.
3. Add active cooling (e.g., 120mm USB fan under the device).
4. Disable Wi-Fi 6 (use Wi-Fi 5 / AC mode) to lower thermal load.
5. Use external router in AP mode if bridge mode fails.
6. Change admin password immediately and avoid using HTTP over untrusted networks.

1. Identify Your Current Firmware Version

1. Connect to the MC801A (WiFi or Ethernet).
2. Open a browser and go to http://192.168.0.1 (or http://192.168.1.1).
3. Login (default credentials: admin / admin or admin / password – check sticker on router).
4. Go to Settings → Device Information.
5. Look for Software Version (e.g., BD_MC801AV1.0.0B12).

Common 2021 versions:
B06, B09, B12, B13, B15

3.3 Bridge Mode Broken

• Issue: Enabling bridge mode on 2021 firmware often resulted in WAN-side DHCP failures or complete loss of web UI access.
• Status: Confirmed broken in B01–B03; partially fixed in B06 (still required manual IP assignment).

3. Critical Issues in 2021 Firmware

1. The "Stability Fix" (Early 2021 – Versions: B04, B05)

In Q1 2021, the first major wave of updates rolled out. These were reactive, fixing the spontaneous reboots that frustrated users.

• Key Changes: Resolved the memory leak causing the device to restart every 48-72 hours.
• User Impact: Improved uptime drastically. Users reported months of continuous operation.
• Downside: No new features; merely a bug fix.

3.5 Poor IPv6 Implementation

• Problem: IPv6 lease renewal often failed, breaking connectivity for IPv6-only services (e.g., some streaming, gaming).
• Impact: Users had to disable IPv6 in LAN settings to maintain stability.