🔐 Karlo Luiten

FIX: Collabora APT/DEB error NO_PUBKEY D8915E456E7C440E (signatures couldn’t be verified)

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by

karlo
in ,

I got these errors:

W: GPG error: https://www.collaboraoffice.com/repos/CollaboraOnline/CODE-deb ./ InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D8915E456E7C440E

W: Failed to fetch https://www.collaboraoffice.com/repos/CollaboraOnline/CODE-ubuntu2004/./InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D8915E456E7C440E

It seems a key was rotated.

First check if there is indeed an old key:

# grep Signed-By /etc/apt/sources.list.d/collaboraonline.sources 

Signed-By: /usr/share/keyrings/collaboraonline-release-keyring.gpg

Check out the keyring file

gpg --show-keys /usr/share/keyrings/collaboraonline-release-keyring.gpg

pub   rsa2048 2013-11-27 [SC]                                                                                               
      6CCEA47B2281732DF5D504D00C54D189F4BA284D                                                                                                                                                                                                           
uid                      Collabora Productivity <libreoffice@collabora.com>

That’s not key D8915E456E7C440E.

Fix

Let’s get it:

wget -O /usr/share/keyrings/collaboraonline-release-keyring.gpg https://collaboraoffice.com/downloads/gpg/collaboraonline-release-keyring.gpg

You might need sudo (sudo wget).

Now check the keys:

# gpg --show-keys /usr/share/keyrings/collaboraonline-release-keyring.gpg
pub   rsa2048 2025-06-17 [SC]
      7EB1530818B7683284483B7BD8915E456E7C440E
uid                      Collabora Productivity (Release Package Signing Key) <hello@collaboraoffice.com>
sub   rsa2048 2025-06-17 [E]

Whoo! That’s key 7EB1530818B7683284483B7BD8915E456E7C440E.

Now apt-update will work.