{"id":"EEF-CVE-2026-47078","summary":"Relative path traversal in zip:unzip/zip:extract via check_dir_level depth-counter bypass","details":"## Summary\n\nRelative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive.\n\n`zip:unzip/1,2` and `zip:extract/1,2` validate entry paths using `zip:check_dir_level/2`, which tracks directory depth as a running integer counter: `..` decrements it, normal path components increment it. The caller rejects only paths where the final counter value is less than zero. A path such as `../x/y` causes the counter to go negative mid-traversal then recover to zero, passing validation while resolving to a location outside the extraction directory when joined with the current working directory via `add_cwd`.\n\nThis vulnerability is associated with program file `lib/stdlib/src/zip.erl`.\n\nThis issue affects OTP from OTP 27.1 before OTP 27.3.4.15, OTP 28.5.0.4, and OTP 29.0.4, corresponding to stdlib from 6.1 before 6.2.2.4, 7.3.0.1, and 8.0.3.","aliases":["CVE-2026-47078","GHSA-rf72-wp7h-jg3x"],"modified":"2026-09-24T21:00:03.695623146Z","published":"2026-07-27T15:03:50.929Z","database_specific":{"cwe_ids":["CWE-23"],"capec_ids":["CAPEC-139"],"cpe_ids":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://github.com/erlang/otp/security/advisories/GHSA-rf72-wp7h-jg3x"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-47078.html"},{"type":"WEB","url":"https://www.erlang.org/doc/system/versions.html#order-of-versions"},{"type":"WEB","url":"https://github.com/erlang/otp/commit/8d537f51a4262d24f3395c4148323eaca9facbbd"},{"type":"FIX","url":"https://github.com/erlang/otp/commit/8a933c9c7835b06776d31d17b79b7336627d887a"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/erlang/otp","events":[{"introduced":"8d537f51a4262d24f3395c4148323eaca9facbbd"},{"fixed":"8a933c9c7835b06776d31d17b79b7336627d887a"}]}],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-47078.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L"}],"credits":[{"name":"Jonatan Männchen / EEF","type":"FINDER"},{"name":"Zhang Delong","type":"FINDER"},{"name":"John Högberg","type":"REMEDIATION_DEVELOPER"}]}