T42S Latest Firmware

[Daniel350]

Have 2 Yealink T42S Phones on 3CX. 3CX dashboard is warning Unsupported Firmware and later available. Phones have 66.86.0.160 which according to Yealink is latest Version. 3CX States latest is 66.86.0.180 but obviously fails on Auto update.

 

[Voiceking.be]

Thread 'Yealink Firmware Updates for Legacy Models'

Oct 16, 2025

New firmware ensures compatibility with 3CX V20 Update 7.​

Yealink has finally released new firmware for several legacy and end-of-life (EOL) phone models. These updates address a security issue recently reported by the U.S. Cybersecurity and Infrastructure Security Agency (CISA), registered under ICSA-25-219-08. 3CX has verified intero...

Continue reading the Original Blog Post.

• Pierre_3CX
• Replies: 6
• Forum: Product Releases

• 

I think this will help you.

 

[JohnS_3CX]

Hi Daniel,

Can you please elaborate? Give us a detailed description of what you did and what you observed.

 

[mike748]

Hello,

We have the same issue with the Yealink T46S: when trying to upgrade as follows:



We get the following error:



Many thanks for your help.

Best regards,

Michel

 

[SteveITS]

Try: https://www.3cx.com/community/threads/yealink-firmware-updates-for-legacy-models.135392/#post-647356

 

[mike748]

Try: https://www.3cx.com/community/threads/yealink-firmware-updates-for-legacy-models.135392/#post-647356

Many thanks for your help, this solved the problem!