What’s Vulnerable › Vulnerabilities

CVE-2026-86071: Junrar: LocalFolderExtractor mkdir escape allows directory creation outside extraction root

• Severity: low (CVSS 3.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-16 · updated 2026-09-24
• Weakness: CWE-22

Description

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.

Affected products

• junrar: before 7.6.1

References

• https://github.com/junrar/junrar/commit/e6e333b195a1e3ad271a18fd79d8ac1eb5289343
• https://github.com/junrar/junrar/releases/tag/v7.6.1
• https://github.com/junrar/junrar/security/advisories/GHSA-89m4-43j5-vhhx

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