CVE-2026-45398
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.33% probability · 26th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Affected
- openwebui/open webui
- Source
- security-advisories@github.com
References
- https://github.com/open-webui/open-webui/pull/22109Issue Tracking, Patch
- https://github.com/open-webui/open-webui/releases/tag/v0.9.5Release Notes
- https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9Exploit, Mitigation, Vendor Advisory
- https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9Exploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.