{"id":"CVE-2026-57079","title":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata.\n\nNet::BitTorrent validates file path components only on the .torrent-file ingest path","summary":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata.\n\nNet::BitTorrent validates file path components only on the .torrent-file ingest path. The peer and m…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-22"],"published":"2026-06-30","updated":"2026-07-20","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-57079","references":[{"url":"https://github.com/sanko/Net-BitTorrent.pm/security/advisories/GHSA-5wc6-r65f-62rr","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/SANKO/Net-BitTorrent-v2.1.0/changes","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"}],"tags":["nvd"],"epss":0.00403,"epssPercentile":0.34263,"ingestedAt":"2026-07-20T07:36:55.561Z","slug":"CVE-2026-57079","body":"## Overview\n\nNet::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata.\n\nNet::BitTorrent validates file path components only on the .torrent-file ingest path. The peer and magnet metadata path (_on_metadata_received, reached from the BEP09 ut_metadata extension) passes attacker-supplied file names straight to Storage::add_file and Storage::_parse_file_tree, where Path::Tiny's child() does not collapse \"..\". A v2 file tree key, a v1 files[].path element, or a single-file name containing \"..\" segments therefore resolves outside the download directory.\n\nBecause the peer also controls the piece hashes and the served bytes, content verification passes, so a malicious magnet or peer writes attacker-chosen content to an attacker-chosen path on the downloading host.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}