CVE-2026-82049: tarfile extraction filters allow file modification and content disclosure via hard link to symlink
In CPython 3.13 and earlier, the tarfile module's data and tar extraction filters are vulnerable to crafted archives containing a hard link to a symbolic link. Such archives may cause extraction to modify the permissions or modification time of a file outside the destination directory, or expose the contents of that file within the extracted tree.
Affected Software
Event History
Frequently Asked Questions
What conditions are required for exploitation?
An application must extract an attacker-crafted tar archive using the tarfile module's data or tar extraction filter. The archive needs to contain a hard link that targets a symbolic link.
What systems or files could be affected?
The issue can affect files outside the intended extraction destination. Successful exploitation may change an outside file's permissions or modification time, or make that file's contents accessible inside the extracted directory tree.
Are applications using extraction filters protected from this issue?
No. The vulnerable behavior specifically affects the tarfile module's data and tar extraction filters in CPython 3.13 and earlier.