CVE-2026-47078
Severity CVSS v4.0:
MEDIUM
Type:
CWE-23
Relative Path Traversal
Publication date:
27/07/2026
Last modified:
27/07/2026
Description
Relative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive.<br />
<br />
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.<br />
<br />
This vulnerability is associated with program file lib/stdlib/src/zip.erl.<br />
<br />
This issue affects OTP from OTP 27.1 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to stdlib from 6.1 before 8.0.3, 7.3.0.1 and 6.2.2.4.
Impact
Base Score 4.0
4.80
Severity 4.0
MEDIUM
References to Advisories, Solutions, and Tools
- https://cna.erlef.org/cves/CVE-2026-47078.html
- https://github.com/erlang/otp/commit/8a933c9c7835b06776d31d17b79b7336627d887a
- https://github.com/erlang/otp/security/advisories/GHSA-rf72-wp7h-jg3x
- https://osv.dev/vulnerability/EEF-CVE-2026-47078
- https://www.erlang.org/doc/system/versions.html#order-of-versions