`-----BEGIN PGP SIGNATURE-----` is allowed multiple times

[bwbroersma]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Contact: https://example.org
Expires: 2024-12-31T23:59:59Z
Canonical: https://example.org/.well-known/security.txt
-----BEGIN PGP SIGNATURE-----
-----BEGIN PGP SIGNATURE-----

iHUEARYIAB0WIQRycB5RkOs+wpg9n6EnTmJIVFicwwUCZ0nSzgAKCRAnTmJIVFic
w9wAAP9R0rDI4gC6XCiQvwE2rW5Rl+L4tWHT41uAxe2fjtY0sAEA9nY903oadTiK
lvRAba/Ad901rKj/78HD0EnN3kaQRAU=
=BC3U
-----END PGP SIGNATURE-----

This is considered valid, while it is not.

[DigitalTrustCenter]

Thanks for reporting this issue.
This seems to be an issue with the PGP format checking. In the PGPy-dtc library it checks the formatting with a regex which checks if the line exists and is in the correct location. Since it checks the PGP message line by line it does not give an error. We have solved this issue in the PGPy-dtc to include a check that these lines are only included once.
In this case it will now give a pgp_data_error