GnuPG can be made to spin on a relatively small input by (for example) crafting a public key with thousands of signatures attached, compressed down to just a few KB.
https://security.netapp.com/advisory/ntap-20230324-0001/
https://bugzilla.redhat.com/show_bug.cgi?id=2127010
https://access.redhat.com/security/cve/CVE-2022-3219
https://marc.info/?l=oss-security&m=165696590211434&w=4
https://dev.gnupg.org/T5993
https://dev.gnupg.org/D556
Source: Mitre, NVD
Published: 2023-02-23
Updated: 2025-03-12
Base Score: 1.7
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:P
Severity: Low
Base Score: 3.3
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS: 0.00012