Cpython: [CVE-2026-82049] tarfile extraction filters allow file modification and content disclosure via hard link to symlink

[Alan Coopersmith <alan.coopersmith () oracle com>]

-------- Forwarded Message --------
Subject: 	[Security-announce][CVE-2026-82049] tarfile extraction filters allow 
file modification and content disclosure via hard link to symlink
Date:   Mon, 14 Sep 2026 17:59:38 +0100
From:   Stan Ulbrych via Security-announce <security-announce () python org>
Reply-To:       security-sig () python org
To:     security-announce () python org
CC:     Stan Ulbrych <stanulbrych () gmail com>

There is a HIGH severity vulnerability affecting CPython.

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.

Please see the linked CVE ID for the latest information on affected versions:

* https://www.cve.org/CVERecord?id=CVE-2026-82049
* https://github.com/python/cpython/pull/157192

--
Stan Ulbrych  (https://stan.ulbrych.org <https://stan.ulbrych.org>)
_______________________________________________
Security-announce mailing list -- security-announce () python org
https://mail.python.org/mailman3//lists/security-announce.python.org