Local File Inclusion in NiceGUI leaflet component
Noroxi assessment
Priority: Monitor (action score 32/100)
- 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: 0.76% (FIRST EPSS); higher than 54% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: zauberzeug nicegui 1.4.21.
Low priority for now. Upgrade to zauberzeug nicegui 1.4.21 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
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NiceGUI is an easy-to-use, Python-based UI framework. A local file inclusion is present in the NiceUI leaflet component when requesting resource files under the `/_nicegui/{__version__}/resources/{key}/{path:path}` route. As a result any file on the backend filesystem which the web server has access to can be read by an attacker with access to the NiceUI leaflet website. This vulnerability has been addressed in version 1.4.21. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Published
- Apr 12, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.8% · 54th percentile
- CWE
- CWE-22
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.8%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 8.2
- 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.
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.
| Vendor | Product | CPE |
|---|---|---|
| zauberzeug | nicegui | cpe:2.3:a:zauberzeug:nicegui |
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.
zauberzeug nicegui
- >= 1.4.6, < 1.4.21affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| PyPI | nicegui | from 1.4.6 · before 1.4.21 | 1.4.21 |
Same product
zauberzeug: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-25732NiceGUI's Path Traversal via Unsanitized FileUpload.name Enables Arbitrary File Write31Monitor
- CVE-2026-45553NiceGUI: Local file disclosure via Docutils file insertion in ui.restructured_text()30Monitor
- CVE-2026-39844NiceGUI has a Path Traversal in NiceGUI Upload Filename on Windows via Backslash Bypass of PurePosixPath Sanitization30Monitor
- CVE-2025-66645NiceGUI Path Traversal Vulnerability in app.add_media_files() Allows Arbitrary File Reading30Monitor
- CVE-2025-21618NiceGUI On Air authentication issue30Monitor
- CVE-2026-33332NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion27Monitor
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 |
|---|---|---|
| zauberzeug nicegui | 1.4.21 · description | Vendor (CNA) |
| PyPI:nicegui | 1.4.21 | 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.
No nightly-computed relations.
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.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
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
- github.com/zauberzeug/nicegui/commit/ed12eb14f2a6c48b388a05c04b3c5a107ea9d330
- github.com/zauberzeug/nicegui/security/advisories/GHSA-mwc7-64wg-pgvj
- huntr.com/bounties/29ec621a-bd69-4225-ab0f-5bb8a1d10c67
Vendor advisories and official records. Exploit/PoC links are deliberately left out.