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.
Exploitability
AV:LAC:HPR:NUI:NScope
S:UImpact
C:NI:LA:N2.9/CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NOther