pypdf is a free and open-source pure-python PDF library. Prior to 6.12.2, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires extracting the text of a page which contains a form XObject with self-references. This vulnerability is fixed in 6.12.2.
1:1.13-31.26.0-21.26.0-3ubuntu11.26.0-3ubuntu1.20.04.11.26.0-3ubuntu1.20.04.21.26.0-41.26.0-4ubuntu0.22.04.11.26.0-4ubuntu0.22.04.23.17.4-13.4.1-14.0.0-14.0.1-14.0.2-12.12.1-32.12.1-44.3.1-15.4.0-15.4.0-16.9.2-11.23+git20141008-11.25.1-11.25.1-1ubuntu0.1~esm11.25.1-1ubuntu0.1~esm21.26.0-21.26.0-2ubuntu0.1~esm11.26.0-2ubuntu0.1~esm2Exploitability
AV:LAC:LAT:NPR:NUI:NVulnerable System
VC:NVI:NVA:HSubsequent System
SC:NSI:NSA:NCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N