Bug#1138859: Archive-Tar: CVE-2026-42497

[Niko Tyni]

Package: perl
Version: 5.40.1-6
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org
Forwarded: https://github.com/jib/archive-tar-new/commit/17c873492a05eddc0de18c1485e0b2cccd5a9158
Control: found -1 5.32.1-4
Control: found -1 5.36.0-1
Control: found -1 5.42.2-1

The following vulnerability was published[0] for Archive-Tar (bundled with perl):

  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.
  
[0] https://lists.security.metacpan.org/cve-announce/msg/40396457/

-- 
Niko Tyni       ntyni at debian.org