---
id: CVE-2026-47078
title: >-
  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…
summary: >-
  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…
severity: medium
cvss: 4.8
cvssVector: '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'
cwe:
  - CWE-23
vendor: Erlang
product: otp
affected:
  - otp >= 27.1 < *
  - stdlib >= 6.1 < *
  - >-
    erlang/otp >= 8d537f51a4262d24f3395c4148323eaca9facbbd <
    8a933c9c7835b06776d31d17b79b7336627d887a
published: '2026-07-27'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:17:12.687'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-47078'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-47078.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/erlang/otp/commit/8a933c9c7835b06776d31d17b79b7336627d887a
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/erlang/otp/commit/8d537f51a4262d24f3395c4148323eaca9facbbd
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://github.com/erlang/otp/security/advisories/GHSA-rf72-wp7h-jg3x'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-47078'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://www.erlang.org/doc/system/versions.html#order-of-versions'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-27T18:38:46.508080Z'
cvssSource: cna
epss: 0.00192
epssPercentile: 0.07881
ingestedAt: '2026-09-24T21:52:59.713Z'
---

## Overview

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 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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.