CMS (Cryptographic Message Syntax) parsing in gpgsm in GnuPG through 2.5.20 mishandles the CMS format for AES-GCM because aes-ICVlen is supposed to be 12 bytes but 4 bytes is accepted. NOTE: this is related to CVE-2026-34182.

In GnuPG before 2.5.17, a stack-based buffer overflow exists in tpm2daemon during handling of the PKDECRYPT command for TPM-backed RSA and ECC keys.

In GnuPG before 2.5.17, a crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped session key can cause a stack-based buffer overflow in gpg-agent during PKDECRYPT--kem=CMS handling. This can easily be leveraged for denial of service; however, there is also memory corruption that could lead to remote code execution.

In GnuPG before 2.5.17, a long signature packet length causes parse_signature to return success with sig->data[] set to a NULL value, leading to a denial of service (application crash).