CVE-2026-71209
Description
audiobookshelf's authentication-exemption check (server/routers/Auth.js) matches unauthenticated-allowed GET routes against req.path via a regex requiring a literal /items/:id/cover or /authors/:id/image shape, where req.path retains %2F sequences URL-encoded. Express's router decodes the :id route parameter before handler code runs, so a %2F-encoded '../' sequence in :id (e.g. ..%2f..%2f..%2ftmp%2fpwned) passes the literal-path auth-exemption check while resolving to a real path-traversal payload once decoded. CacheManager.handleCoverCache then joins this decoded value into a cache file path and streams the result before any database-backed ownership check. This bypasses the fix applied for CVE-2025-25205 (which anchored the exemption regex and switched it to req.path) and results in unauthenticated arbitrary file read of any file matching the pattern *_<width>[x<height>].<ext> that the service account can read.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
CWEs
CWE-22
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.