How severe is CVE-2026-45666?

CVE-2026-45666 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-45666 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45666?

CVE-2026-45666 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45666?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-45666 have an EU (EUVD) identifier?

Yes. CVE-2026-45666 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30647.

When was CVE-2026-45666 published?

CVE-2026-45666 was published on 2026-05-15 and last updated on 2026-06-17.

CVE-2026-45666

CVE-2026-45666 is a medium-severity vulnerability in Openwebui Open Webui with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30647
Weakness: CWE-639
Affected product: Openwebui Open Webui
Published: 2026-05-15
Last modified: 2026-06-17

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.11, the API /api/v1/notes/{note_id} endpoint lacks proper authorization checks, allowing authenticated users to retrieve notes belonging to other users by guessing or enumerating UUIDs. This results in unauthorized disclosure of potentially sensitive or private user data. This vulnerability is fixed in 0.8.11.

Frequently asked questions

What is CVE-2026-45666?: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.11, the API /api/v1/notes/{note_id} endpoint lacks proper authorization checks, allowing authenticated users to retrieve notes belonging to other users by guessing or enumerating UUIDs. This results in unauthorized disclosure of potentially sensitive or private user data. This vulnerability is fixed in 0.8.11.
How severe is CVE-2026-45666?: CVE-2026-45666 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-45666 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45666?: CVE-2026-45666 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45666?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-45666 have an EU (EUVD) identifier?: Yes. CVE-2026-45666 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30647.
When was CVE-2026-45666 published?: CVE-2026-45666 was published on 2026-05-15 and last updated on 2026-06-17.

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-x3qm-p8hr-3c3h

Affected products (1)

cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*

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