Vulnerability · Published May 15, 2026 · Assigned by GitHub_M
CVE-2026-45398Open WebUI: IDOR - Retrieval API Bypasses Knowledge Base Access Controls
High 7.5
In plain English
A high-severity authorization bypass via user-controlled key in open-webui from open-webui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, _validate_collection_access() checks the user-memory-* and file-* collection name prefixes but does not check knowledge base collections, which use raw UUIDs as collection names. Any authenticated user who knows a private knowledge base UUID can read its content through the retrieval query endpoints, even though the knowledge API correctly denies that user access. The same gap affects the retrieval write endpoints (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), allowing an attacker to inject content into or overwrite another user's knowledge base. This vulnerability is fixed in 0.9.5.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | open-webui | 0.9.5 | GHSA-4g37-7p2c-38r9 |
| PyPI | open-webui | 0.9.5 | PYSEC-2026-2699 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| open-webui | open-webui | < 0.9.5 |
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 x_refsource_CONFIRM
- https://github.com/open-webui/open-webui/pull/22109 x_refsource_MISC
- https://github.com/open-webui/open-webui/releases/tag/v0.9.5 x_refsource_MISC