CVE-2026-44556 json
Open WebUI: responses passthrough endpoint lacks access control authorization
published 2026-05-08 6 mo ago modified 2026-07-13 3 mo ago also GHSA-hp5m-24vp-vq2q , PYSEC-2026-2734 , EUVD-2026-30624
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the /responses endpoint in the OpenAI router accepts any authenticated user and forwards requests directly to upstream LLM providers without enforcing per-model access control. While the primary chat completion endpoint (generate_chat_completion) checks model ownership, group membership, and AccessGrants before allowing a request, the /responses proxy only validates that the user has a valid session via get_verified_user. This allows any authenticated user to interact with any model configured on the instance by sending a POST request to /api/openai/responses with an arbitrary model ID. This vulnerability is fixed in 0.9.0.
Patch / fix
- pypi open-webui 0.9.0
- openwebui open_webui 0.9.0
- github.com/open-webui/open-webui#23481 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H |
| OSV | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H |
| GitHub | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | open-webui | <0.9.0 |
0.9.0 |
Affected products
- open-webui open-webui
Classification
References
-
github.com
/open-webui/open-webui/pull/23481
web
-
github.com
/open-webui/open-webui/security/advisories/GHSA-hp5m-24vp-vq2q
web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-44556
advisory
-
github.com
/open-webui/open-webui
package
-
pypi.org
/project/open-webui
package
-
github.com
/advisories/GHSA-hp5m-24vp-vq2q
advisory
Sources
- CVE List CVE-2026-44556
- GitHub Advisory GHSA-hp5m-24vp-vq2q
- NVD CVE-2026-44556
- OSV PYSEC-2026-2734
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