Is CVE-2026-45398 actively exploited?

No active exploitation of CVE-2026-45398 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-45398 be exploited remotely?

Yes. CVE-2026-45398 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-45398?

CVE-2026-45398 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-45398

HIGH

CVE-2026-45398

CWE-639Published: May 15, 2026· Updated: May 19, 2026

7.5

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:11.4th

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.

NVD Source

Technical Analysis

CVE-2026-45398 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.5.