Ubuntu has published a security advisory, highlighting vulnerabilities in the Linux kernel (3rd June, 2021). It is recommended that you take the necessary precautions by ensuring your products are always updated.
The affected products are:
Ubuntu 18.04 LTS
Ubuntu 16.04 ESM
Ubuntu 14.04 ESM
Ubuntu 20.04 LTS
For more information on these updates, you can follow these URLs:
Ubuntu Security Notice (USN-4977-1)
https://ubuntu.com/security/notices/USN-4977-1
Ubuntu Security Notice (USN-4979-1)
https://ubuntu.com/security/notices/USN-4979-1
Ubuntu Security Notice (USN-4982-1)
https://ubuntu.com/security/notices/USN-4982-1
Ubuntu Security Notice (USN-4983-1)
https://ubuntu.com/security/notices/USN-4983-1
The Guyana National CIRT recommends that users and administrators review these updates and apply them where necessary.
PDF Download: Ubuntu Releases Security Updates for Thunderbird.pdf
References