USN-4516-1: GnuPG vulnerability

17 September 2020

GnuPG could be made to expose sensitive information.



  • gnupg2 - GNU privacy guard - a free PGP replacement


It was discovered that GnuPG signatures could be forged when the SHA-1
algorithm is being used. This update removes validating signatures based on
SHA-1 that were generated after 2019-01-19. In environments where this is
still required, a new option --allow-weak-key-signatures can be used to
revert this behaviour.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04

In general, a standard system update will make all the necessary changes.