CVE-2026-42885 json
Audiobookshelf: Path prefix bypass in filesystem existence check leaks out-of-scope file existence
published 2026-05-11 5 mo ago modified 2026-10-26 13 d ago also EUVD-2026-29208
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 20%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-rhjg-p6cm-38w2 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |
Affected products
- advplyr audiobookshelf
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
Sources
- CVE List CVE-2026-42885
- NVD CVE-2026-42885
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