CVE-2026-45398

Name: CVE-2026-45398
Creator: NVD / NIST
Published: 2026-05-15T21:16:37.863+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.33%

Last modified Jun 17, 2026

CVE-2026-45398 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.33% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.33%

24.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-639

Affected Software

Vendor	Product	Versions
Openwebui	Open Webui	< 0.9.5

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

Timeline

Published: May 15, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-45398?

How severe is CVE-2026-45398?

CVE-2026-45398 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2026-45398?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-45398?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST