Relative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive.

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.

This vulnerability is associated with program file lib/stdlib/src/zip.erl.

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.

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No workaround given by the vendor.

History

Fri, 31 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-22
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L'}

threat_severity

Moderate


Tue, 28 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 27 Jul 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Erlang erlang/otp
Vendors & Products Erlang erlang/otp

Mon, 27 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description Relative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive. 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. This vulnerability is associated with program file lib/stdlib/src/zip.erl. This issue affects OTP from OTP 27.1 before 27.3.4.15, 28.5.0.4, and 29.0.4 corresponding to stdlib from 6.1 before 6.2.2.4, 7.3.0.1, and 8.0.3. Relative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive. 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. This vulnerability is associated with program file lib/stdlib/src/zip.erl. 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.

Mon, 27 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Description Relative Path Traversal vulnerability in Erlang OTP (stdlib zip module) allows writing files outside the intended extraction directory via a crafted zip archive. 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. This vulnerability is associated with program file lib/stdlib/src/zip.erl. This issue affects OTP from OTP 27.1 before 27.3.4.15, 28.5.0.4, and 29.0.4 corresponding to stdlib from 6.1 before 6.2.2.4, 7.3.0.1, and 8.0.3.
Title Relative path traversal in zip:unzip/zip:extract via check_dir_level depth-counter bypass
First Time appeared Erlang
Erlang erlang\/otp
Weaknesses CWE-23
CPEs cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*
Vendors & Products Erlang
Erlang erlang\/otp
References
Metrics cvssV4_0

{'score': 4.8, 'vector': '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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-07-28T09:53:55.522Z

Reserved: 2026-05-18T17:28:10.319Z

Link: CVE-2026-47078

cve-icon Vulnrichment

Updated: 2026-07-27T18:38:50.891Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-27T15:03:50Z

Links: CVE-2026-47078 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-03T17:30:17Z

Weaknesses