CVE-2026-45303 json
Open WebUI: Stored XSS via the HTML renedering view
published 2026-05-14 5 mo ago modified 2026-07-13 3 mo ago also EUVD-2026-30654 , GHSA-4vrc-m9ch-6m3r , PYSEC-2026-2704
- cvss
- 7.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 13%
- public exploits
- 0
- none known
Summary
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.6.5, through the HTML rendering view, scripts can be injected and executed. The frontend provides a function to visualize the HTML content of a current chat. The content is embedded in an iFrame with the allow-scripts allow-forms allow-same-origin sandbox directive. This means that the content is placed in a sandbox but with permission to execute scripts and access the parent’s data (e.g., local storage). As a result, only a few functions are restricted (e.g., displaying an alert box), but in effect, the sandbox attribute is largely nullified. This vulnerability is fixed in 0.6.5.
Patch / fix
- pypi open-webui 0.6.5
- openwebui open_webui 0.6.5
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 5 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N |
| GitHub | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N |
| OSV | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | open-webui | <0.6.5 |
0.6.5 |
Affected products
- open-webui open-webui
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r
exploit, web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-45303
advisory
-
github.com
/open-webui/open-webui
package
-
pypi.org
/project/open-webui
package
-
github.com
/advisories/GHSA-4vrc-m9ch-6m3r
advisory
Sources
- CVE List CVE-2026-45303
- GitHub Advisory GHSA-4vrc-m9ch-6m3r
- NVD CVE-2026-45303
- OSV PYSEC-2026-2704
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.