tarfile.data_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.
Exploitability
AV:NAC:LAT:NPR:NUI:AVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:NSA:N6.9/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NInput Validation