I think this issue also affects communicating with netfilter.org: $ gnutls-cli netfilter.org Processed 127 CA certificate(s). Resolving 'netfilter.org:443'... Connecting to '92.243.18.11:443'... - Certificate type: X.509 - Got a certificate list of 4 certificates. - Certificate[0] info: - subject `CN=iptables.org', issuer `CN=R3,O=Let's Encrypt,C=US', serial 0x0330e74e9bb6f125ade3afb49b7c8d47d0ee, RSA key 2048 bits, signed using RSA-SHA256, activated `2022-07-10 21:33:49 UTC', expires `2022-10-08 21:33:48 UTC', pin- sha256="1E+Rv29dI0tS3XaAhXc8qjGHah4UCYzzBpTpG1Mar28=" Public Key ID: sha1:ac3fc835851d492debd58a41df39d1adfcb12292 sha256:d44f91bf6f5d234b52dd768085773caa31876a1e14098cf 30694e91b531aaf6f Public Key PIN: pin- sha256:1E+Rv29dI0tS3XaAhXc8qjGHah4UCYzzBpTpG1Mar28=
- Certificate[1] info: - subject `CN=iptables.org', issuer `CN=R3,O=Let's Encrypt,C=US', serial 0x0330e74e9bb6f125ade3afb49b7c8d47d0ee, RSA key 2048 bits, signed using RSA-SHA256, activated `2022-07-10 21:33:49 UTC', expires `2022-10-08 21:33:48 UTC', pin- sha256="1E+Rv29dI0tS3XaAhXc8qjGHah4UCYzzBpTpG1Mar28=" - Certificate[2] info: - subject `CN=R3,O=Let's Encrypt,C=US', issuer `CN=ISRG Root X1,O=Internet Security Research Group,C=US', serial 0x00912b084acf0c18a753f6d62e25a75f5a, RSA key 2048 bits, signed using RSA-SHA256, activated `2020-09-04 00:00:00 UTC', expires `2025-09-15 16:00:00 UTC', pin- sha256="jQJTbIh0grw0/1TkHSumWb+Fs0Ggogr621gT3PvPKG0=" - Certificate[3] info: - subject `CN=ISRG Root X1,O=Internet Security Research Group,C=US', issuer `CN=DST Root CA X3,O=Digital Signature Trust Co.', serial 0x4001772137d4e942b8ee76aa3c640ab7, RSA key 4096 bits, signed using RSA-SHA256, activated `2021-01-20 19:14:03 UTC', expires `2024-09-30 18:14:03 UTC', pin- sha256="C5+lpZ7tcVwmwQIMcRtPbsQtWLABXhQzejna0wHFr8M=" - Status: The certificate is NOT trusted. The certificate issuer is unknown. *** PKI verification of server certificate failed... *** Fatal error: Error in the certificate. -- Jean Parpaillon