An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires extracting text in layout mode with large character offsets.
This has been fixed in pypdf==6.12.0.
If developers are unable to immediately upgrade, they should consider applying the changes from PR #3790.
6.12.0Exploitability
AV:LAC:LAT:NPR:NUI:PVulnerable System
VC:NVI:NVA:LSubsequent System
SC:NSI:NSA:N4.8/CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N