Cross-user note disclosure via missing ownership check
Published May 15, 2026 · Updated May 15, 2026
Authorization bypass in Open WebUI before 0.8.11 allows remote authenticated users to read other users' notes via crafted note UUIDs. The GET /api/v1/notes/{note_id} handler retrieves a note by its caller-controlled identifier without verifying ownership or an access grant. Any valid account can obtain or enumerate a note UUID and receive its contents even when the Notes interface is disabled; no write or deletion impact is reported.
Summary
What happened
Authorization bypass in Open WebUI before 0.8.11 allows remote authenticated users to read other users' notes via crafted note UUIDs. The GET /api/v1/notes/{note_id} handler retrieves a note by its caller-controlled identifier without verifying ownership or an access grant. Any valid account can obtain or enumerate a note UUID and receive its contents even when the Notes interface is disabled; no write or deletion impact is reported.
The record
- CVE
- CVE-2026-45666
- Published
- May 15, 2026
- Updated
- May 15, 2026
- Vendor
- Open WebUI
- Product
- Open WebUI
- Classifications
- CWE-639, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 15, 2026CVE publishedPublication date reported by the CVE source.
- May 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.8.11
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Authenticated cross-user note retrieval proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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