CVE-2026-86071 PUBLISHED

Junrar: LocalFolderExtractor mkdir escape allows directory creation outside extraction root

Assigner: GitHub_M
Reserved: 04.09.2026 Published: 16.09.2026 Updated: 16.09.2026

Junrar is an open source Java RAR archive library. Prior to version 7.6.1, LocalFolderExtractor in src/main/java/com/github/junrar/LocalFolderExtractor.java can create directories outside the intended extraction root when processing a crafted archive entry. LocalFolderExtractor.createFile() validates only the final canonical file path, while LocalFolderExtractor.makeFile() creates intermediate path segments with unchecked mkdir() calls. An entry can therefore make the final path resolve inside the destination while causing intermediate directory creation outside it, enabling filesystem pollution or file-versus-directory squatting that can make later security-sensitive writes fail. The demonstrated impact is directory creation, not unconditional arbitrary file-content write. This issue is fixed in version 7.6.1.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS Score: 3.7

Product Status

Vendor junrar
Product junrar
Versions
  • Version < 7.6.1 is affected

References

Problem Types

  • CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE