Relative path traversal in zip:unzip/zip:extract via check_dir_level depth-counter bypass
Summary
| CVE | CVE-2026-47078 |
|---|---|
| State | PUBLISHED |
| Assigner | EEF |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-27 16:17:07 UTC |
| Updated | 2026-07-27 19:17:15 UTC |
| 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 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. |
Risk And Classification
Primary CVSS: v4.0 4.8 MEDIUM from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-23 | CWE-23 CWE-23 Relative Path Traversal
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | Secondary | 4.8 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | CVSS | 4.8 | MEDIUM | 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 |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
PassiveConfidentiality
NoneIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
LowSub Availability
LowCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| cna.erlef.org/cves/CVE-2026-47078.html | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | cna.erlef.org | |
| www.erlang.org/doc/system/versions.html | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | www.erlang.org | |
| osv.dev/vulnerability/EEF-CVE-2026-47078 | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | osv.dev | |
| github.com/erlang/otp/commit/8a933c9c7835b06776d31d17b79b7336627d887a | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| github.com/erlang/otp/security/advisories/GHSA-rf72-wp7h-jg3x | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Jonatan Männchen (en)
CNA: Zhang Delong (en)
CNA: John Högberg (en)
There are currently no legacy QID mappings associated with this CVE.