========================================================================
CVE-2026-42497 CPAN Security Group
========================================================================
CVE ID: CVE-2026-42497
Distribution: Archive-Tar
Versions: before 3.08
MetaCPAN: https://metacpan.org/dist/Archive-Tar
VCS Repo: https://github.com/jib/archive-tar-new
Archive::Tar versions before 3.08 for Perl extract hardlinks to
attacker controlled paths outside the extraction directory
Description
-----------
Archive::Tar versions before 3.08 for Perl extract hardlinks to
attacker controlled paths outside the extraction directory.
_make_special_file() passes the tar header's linkname to link() without
validating it against absolute paths or .. segments, creating a
hardlink that shares the victim file's inode.
A subsequent write through the extracted name modifies the victim file,
and the post-extraction chmod, chown, and utime block in
_extract_file() (guarded only against symlinks via -l) applies the tar
header's mode, owner, and timestamps to the shared inode during
extraction alone.
Problem types
-------------
- CWE-59 Improper Link Resolution Before File Access ('Link Following')
- CWE-732 Incorrect Permission Assignment for Critical Resource
Solutions
---------
Upgrade to Archive::Tar 3.08 or later.
References
----------
https://github.com/jib/archive-tar-new/commit/17c873492a05eddc0de18c1485e0b2cccd5a9158.patch
https://metacpan.org/release/BINGOS/Archive-Tar-3.08/changes
https://www.cve.org/CVERecord?id=CVE-2026-42496
Timeline
--------
- 2026-04-12: Issue reported.
- 2026-05-10: Version 3.06 released, disabling hardlink extraction by
default.
- 2026-05-22: Version 3.08 released.
