File Browser: Cross-user unauthorized share-link deletion via unbounded prefix match in DeleteWithPathPrefix
Noroxi assessment
Priority: Monitor (action score 28/100)
- 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: 0.45% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action 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, a low-privileged authenticated user of filebrowser (with create + delete permissions in their own isolated scope) can silently destroy share-link records belonging to any other user — including the administrator — by performing a legitimate DELETE on a file in their own directory whose logical path happens to be a byte-prefix of another user's stored share.Link.Path. The file contents of the victim are not exposed, but the victim's share links are irrevocably wiped. This vulnerability is fixed in 2.63.6.
- Published
- Jun 25, 2026
- Updated
- Jun 26, 2026
- EPSS
- 0.4% · 37th percentile
- CWE
- CWE-639
Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 7.2
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/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
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
- < 2.63.6affected
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 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-2026-54094Jun 25, 2026 · File Browser: Symlink following lets scoped users read, overwrite, and share files outside their filebrowser scope30Monitor
- ← EarlierCVE-2026-54096Jun 25, 2026 · File Browser: Improper Access Control Occurs via Pre-Created Public Share for a Non-existent Path33Monitor
- Later →CVE-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
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.
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-2026-7361249 days apartFile Browser before v2.63.22 Authorization Bypass via Recursive Operations34Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
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.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-639 · Authorization Bypass Through User-Controlled KeyCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/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
The endpoint fetches the record by the ID sent in the request, but never checks whether the record belongs to the requesting user.
The bug in code
The whole CWE-639 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const invoice = await Invoice.findById(req.params.id);res.json(invoice);Fixed
const invoice = await Invoice.findOne({ id: req.params.id, ownerId: req.user.id,});if (!invoice) return res.sendStatus(404);res.json(invoice);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
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References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.