Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2026-42885 is a medium-severity Path Traversal (CWE-22) vulnerability. Its CVSS base score is 4.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique File and Directory Discovery (T1083); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-29208
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Path traversal in pathexists endpoint directly enables unauthorized file/directory existence probing (T1083 File and Directory Discovery) outside library boundaries.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation of path inputs to the /api/filesystem/pathexists endpoint to reject traversals outside library directories.
Enforces that resolved filesystem paths must stay within authorized library boundaries before any file-existence check succeeds.
Controls information flow by ensuring pathname resolution cannot leak existence data across library-folder boundaries.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.