CVE-2026-55668: File Browser: ScopedFs follows a dangling symlink on write, letting a scoped user create files outside their scope
Noroxi assessment
Priority: Monitor (action score 25/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: filebrowser filebrowser 2.63.16.
Low priority for now. Upgrade to filebrowser filebrowser 2.63.16 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
File Browser provides a web file managing interface. Prior to 2.63.16, ScopedFs validates the nearest existing ancestor of a dangling symlink as in scope and then follows the symlink during file creation, allowing an authenticated user with Create and Modify permissions to create attacker-controlled files outside the user's scope. This issue is fixed in version 2.63.16.
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- EPSS
- 0.3% · 31th percentile
- CWE
- CWE-22
Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 25 / 40 · 6.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 6.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
filebrowser filebrowser
- < 2.63.16affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Go | github.com/filebrowser/filebrowser | from 0 | — |
| Go | github.com/filebrowser/filebrowser/v2 | before 2.63.16 | 2.63.16 |
Same product
filebrowser: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-32760File Browser Self Registration Grants Any User Admin Access When Default Permissions Include Admin40Plan
- CVE-2026-34528File Browser's Signup Grants Execution Permissions When Default Permissions Includes Execution39Monitor
- CVE-2026-72839filebrowser through 2.63.16 Privilege Escalation via Signup37Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-54097Jun 25, 2026 · File Browser: Cross-user unauthorized share-link deletion via unbounded prefix match in DeleteWithPathPrefix28Monitor
- ← EarlierCVE-2026-55667Jun 25, 2026 · File Browser: Out-of-scope file deletion by a Create-only scoped user via symlink-following RemoveAll in upload failure-cleanup32Monitor
- Later →CVE-2026-61874Jul 12, 2026 · filebrowser before 2.63.17 Stale Public Share via Trailing-Slash Delete9Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| filebrowser filebrowser | 2.63.16 · description | Vendor (CNA) |
| Go:github.com/filebrowser/filebrowser/v2 | 2.63.16 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-5566713 days apartFile Browser: Out-of-scope file deletion by a Create-only scoped user via symlink-following RemoveAll in upload failure-cleanup32Monitor
- CVE-2026-5409413 days apartFile Browser: Symlink following lets scoped users read, overwrite, and share files outside their filebrowser scope30Monitor
- CVE-2026-628437 days apartFile Browser: Archive builder turns backslash filenames into path traversal (zip-slip)27Monitor
- CVE-2026-5409313 days apartFile Browser: Path traversal in download-as-zip/tar via Windows-style backslash separators in stored filenames27Monitor
- CVE-2026-32758111 days apartFile Browser has an Access Rule Bypass via Path Traversal in Copy/Rename Destination Parameter26Monitor
- CVE-2026-3560592 days apartFile Browser has an access rule bypass via HasPrefix without trailing separator in path matching25Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2026-5408913 days apartFile Browser: Authentication Bypass via Proxy Auth Header Forgery36Monitor
- CVE-2026-7283637 days apartFileBrowser before 2.63.19 Case Sensitivity Authentication Bypass36Monitor
- CVE-2026-8223651 days apartFile Browser 2.63.6 through 2.63.23 Share Link Exposure via File Deletion9Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N
nvd-secondary
Root cause
A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.
The bug in code
The whole CWE-22 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const file = path.join(ROOT, req.query.name);
res.sendFile(file);Fixed
const file = path.resolve(ROOT, req.query.name);
if (!file.startsWith(ROOT + path.sep)) {
return res.sendStatus(400);
}
res.sendFile(file);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Path TraversalCAPEC-126likelihood: High · Very High
- Using Slashes and URL Encoding Combined to Bypass Validation LogicCAPEC-64likelihood: High · High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
- Using Escaped Slashes in Alternate EncodingCAPEC-78likelihood: High · High
- Using Slashes in Alternate EncodingCAPEC-79likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.