filebrowser before 2.63.19 contains a permission bypass in the /api/resources endpoint. The checksum (?checksum=) branch of resourceGetHandler reads the entire file to compute a digest and returns it without performing a Perm.Download check (unlike the sibling raw, preview, and subtitle paths). As a result, an authenticated user provisioned with Perm.Download=false can obtain a content-hash oracle for any same-scope file (md5/sha1/sha256/sha512), enabling confirmation of known/guessed content, change detection, and offline brute-force of low-entropy files.
This is an incomplete fix of CVE-2026-35606; it bypasses only the Download permission and does not defeat scope/path authorization.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
filebrowser:filebrowser
References 3
https://github.com/filebrowser/filebrowser/commit/b7dc392838f11d188f0bc0f2a1a99…
disclosure@vulncheck.com
https://github.com/filebrowser/filebrowser/security/advisories/GHSA-7whw-q6gh-x…
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/filebrowser-before-permission-bypass-via-c…
disclosure@vulncheck.com