pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires extracting the text in layout mode. This vulnerability is fixed in 6.13.0.
1:1.13-31.26.0-21.26.0-3ubuntu11.26.0-3ubuntu1.20.04.11.26.0-3ubuntu1.20.04.24.3.1-15.4.0-11.23+git20141008-11.25.1-11.25.1-1ubuntu0.1~esm11.25.1-1ubuntu0.1~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