filebrowser: Improper Link Resolution Before File Access
CVE-2026-73613 is a high-severity improper link resolution before file access vulnerability in filebrowser, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.63.19 as the first without the flaw, so updating filebrowser to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update filebrowser to 2.63.19 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Filebrowser | filebrowser | before 2.63.19 | 2.63.19 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.2 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.2 | High | CNA (vulncheck.com) |
Official description
filebrowser versions before 2.63.19 contain an out-of-scope file deletion vulnerability in the TUS upload cache eviction mechanism that allows authenticated users with only Create permission to delete arbitrary files outside their scope. Attackers can swap an ancestor directory with a symlink during the cache TTL window to redirect the raw os.Remove call to an out-of-scope target, bypassing ScopedFs scope guards and Perm.Delete checks.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Link Resolution Before File Access
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
How developers prevent this class of flaw
- Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
More Improper Link Resolution Before File Access vulnerabilities (CWE-59)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in filebrowser
- 8.1 High severity
- 8.8 High severity
- 8.1 High severity
- 9.8 Critical severity
- 8.1 High severity
- 8.1 High severity
Recent Improper Link Resolution Before File Access vulnerabilities
- 7.1 High severity
- 7.8 High severity
- 8.1 High severity
- 7.4 High severity
- 7.1 High severity
- 7.1 High severity
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