What’s Vulnerable › Vulnerabilities

CVE-2026-42885: Audiobookshelf: Path prefix bypass in filesystem existence check leaks out-of-scope file existence

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-11 · updated 2026-10-26
• Weakness: CWE-22

Description

Audiobookshelf is a self-hosted audiobook and podcast server. Prior to 2.32.2, the POST /api/filesystem/pathexists endpoint uses String.startsWith() to validate that a resolved file path is within a library folder. This check fails for sibling directories whose names share a common prefix (e.g., /audiobooks vs /audiobooks-private), allowing authenticated users with upload permission to probe file existence outside their authorized library folder boundaries. This vulnerability is fixed in 2.32.2.

Affected products

• advplyr audiobookshelf: before 2.33.2

References

• https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-rhjg-p6cm-38w2
• https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-rhjg-p6cm-38w2

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