CVE-2026-47078

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_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.

Affected Software

VendorProductVersion RangeStatus
ErlangOTP6.1 < *affected
ErlangOTP27.1 < *affected
ErlangOTP8d537f51a4262d24f3395c4148323eaca9facbbd < 8a933c9c7835b06776d31d17b79b7336627d887aaffected

Weaknesses

  • CWE-23: CWE-23 Relative Path Traversal

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References