NVD / CVE Program· CNA GitHub_M

CVE-2026-54093: File Browser: Path traversal in download-as-zip/tar via Windows-style backslash separators in stored filenames

Noroxi assessment

Priority: Monitor (action score 27/100)

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: 0.19% (FIRST EPSS).
Someone with local access to the system can trigger it. No account or password is required. No special conditions are required; it is repeatable.
Fixed version: filebrowser filebrowser 2.63.6.

Low priority for now. Upgrade to filebrowser filebrowser 2.63.6 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 is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, filebrowser builds the download-as-zip / download-as-tar archive entry names with filepath.ToSlash, which on a Linux host is a no-op for backslashes (\ is only a path separator on Windows). A file whose name contains Windows-style traversal is accepted by the resource handlers, stored on the Linux filesystem with a literal backslash name, and then emitted verbatim as the archive entry name. Windows extractors interpret \ as a path separator and write the extracted file outside the extraction directory — arbitrary file write on the victim who downloads and extracts the archive. This vulnerability is fixed in 2.63.6.

MediumCVSS 6.8 · v4.0—No exploit Fix available

Path traversal

Published: Jun 25, 2026
Updated: Jun 25, 2026
EPSS: 0.1% · 9th percentile
CWE: CWE-22

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 27 / 40 · 6.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

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: 6.8; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

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

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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.

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Affected 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.

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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
- < 2.63.6affected

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	up to and including 1.11.0	—
Go	github.com/filebrowser/filebrowser/v2	before 2.63.6	2.63.6

Same product

filebrowser: all records

Other highest-scoring records for the same primary product.

CVE-2026-32760File Browser Self Registration Grants Any User Admin Access When Default Permissions Include Admin
40Plan
CVE-2026-34528File Browser's Signup Grants Execution Permissions When Default Permissions Includes Execution
39Monitor
CVE-2026-72839filebrowser through 2.63.16 Privilege Escalation via Signup
37Monitor

Published before and after this one in the same product

← EarlierCVE-2026-54091Jun 25, 2026 · File Browser: Incorrect access control in public directory shares via rule path rebasing
30Monitor
← EarlierCVE-2026-54092Jun 25, 2026 · File Browser: DoS Vulnerability on Public Login API
26Monitor
Later →CVE-2026-54094Jun 25, 2026 · File Browser: Symlink following lets scoped users read, overwrite, and share files outside their filebrowser scope
30Monitor

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	2.63.6 · description	Vendor (CNA)
Go:github.com/filebrowser/filebrowser/v2	2.63.6	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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, 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-2026-556670 days apartFile Browser: Out-of-scope file deletion by a Create-only scoped user via symlink-following RemoveAll in upload failure-cleanup
32Monitor
CVE-2026-540940 days apartFile Browser: Symlink following lets scoped users read, overwrite, and share files outside their filebrowser scope
30Monitor
CVE-2026-6284320 days apartFile Browser: Archive builder turns backslash filenames into path traversal (zip-slip)
27Monitor
CVE-2026-3275898 days apartFile Browser has an Access Rule Bypass via Path Traversal in Copy/Rename Destination Parameter
26Monitor
CVE-2026-5566813 days apartFile Browser: ScopedFs follows a dangling symlink on write, letting a scoped user create files outside their scope
25Monitor
CVE-2026-3560579 days apartFile Browser has an access rule bypass via HasPrefix without trailing separator in path matching
25Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
No account or password is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Local
Attack complexity: Low
Privileges required: None
User interaction: P
Scope: X

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.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)

ATT&CK techniques

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Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

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References

github.com/filebrowser/filebrowser/security/advisories/GHSA-gxjx-7m74-hcq8

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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