Open WebUI vulnerable to limited stored XSS vila uploaded html file
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.6.6, low privileged users can upload HTML files which contain JavaScript code via the `/api/v1/files/` backend endpoint. This endpoint returns a file id, which can be used to open the file in the browser and trigger the JavaScript code in the user's browser. Under the default settings, files uploaded by low-privileged users can only be viewed by admins or themselves, limiting the impact of this vulnerability. A link to such a file can be sent to an admin, and if clicked, will give the low-privileged user complete control over the admin's account, ultimately enabling RCE via functions. Version 0.6.6 contains a fix for the issue.
- Published
- May 5, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 29th percentile
- CWE
- CWE-79
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
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
- 5.3
- 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:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:P
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| openwebui | open webui | cpe:2.3:a:openwebui:open_webui |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- openwebui open webuibefore 0.6.6
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.
open-webui open-webui
- < 0.6.6affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| PyPI | open-webui | before 0.6.6 | 0.6.6 |
Same product
openwebui: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-44566Open WebUI: Arbitrary File Upload and Path Traversal39Monitor
- CVE-2026-56400open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation36Monitor
- CVE-2026-59216Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id36Monitor
- CVE-2026-59214Open WebUI: Stored web worker XSS via Pyodide36Monitor
- CVE-2026-44551Open WebUI: LDAP Empty Password Authentication Bypass36Monitor
- CVE-2024-8017Cross-site Scripting (XSS) in open-webui/open-webui36Monitor
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 |
|---|---|---|
| PyPI:open-webui | 0.6.6 | 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-2024-801746 days apartCross-site Scripting (XSS) in open-webui/open-webui36Monitor
- CVE-2026-59214430 days apartOpen WebUI: Stored web worker XSS via Pyodide36Monitor
- CVE-2024-704446 days apartStored XSS in open-webui/open-webui35Monitor
- CVE-2026-44549375 days apartOpen WebUI: Stored XSS in excel file preview34Monitor
- CVE-2026-45315375 days apartOpen WebUI: Stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions34Monitor
- CVE-2026-87995492 days apartOpen WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin34Monitor
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-2024-805346 days apartImproper Authentication in open-webui/open-webui32Monitor
- CVE-2024-798346 days apartDenial of Service in open-webui/open-webui30Monitor
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 special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- A
- Scope
- X
Weakness class (CWE)
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:P/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
User content is inserted into the page as HTML. The browser interprets the content as code rather than data.
The bug in code
The whole CWE-79 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
commentEl.textContent = comment.body;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
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/open-webui/open-webui/blob/main/backend/open_webui/routers/files.py#L434-L438
- github.com/open-webui/open-webui/commit/ef2aeb7c0eb976bac759e59ac359c94a5b8dc7e0
Vendor advisories and official records. Exploit/PoC links are deliberately left out.