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PatchSiren cyber security CVE debrief

CVE-2026-45301 open-webui CVE debrief

Open WebUI versions prior to 0.3.16 contain a missing permission check vulnerability in all files-related API endpoints. Any authenticated user can list, access, and delete files uploaded by any other user on the platform. This represents a broken access control issue (CWE-284) with network-exploitable, low-complexity attack requirements. The vulnerability was disclosed via GitHub Security Advisory and addressed in version 0.3.16. Organizations running self-hosted Open WebUI instances should prioritize upgrading to the patched release, as the platform is designed for offline operation and may handle sensitive AI-related data.

Vendor
open-webui
Product
Unknown
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-15
Original CVE updated
2026-05-18
Advisory published
2026-05-15
Advisory updated
2026-05-18

Who should care

Organizations operating self-hosted Open WebUI instances for offline AI workloads; security teams managing access control for multi-user AI platforms; compliance officers responsible for data segregation in on-premises AI deployments

Technical summary

The vulnerability exists in files-related API endpoints where authorization checks fail to validate file ownership against the requesting user. Authenticated sessions obtain blanket access to file metadata and content regardless of uploader identity. The fix in 0.3.16 implements proper ownership verification before file operations.

Defensive priority

high

Recommended defensive actions

  • Upgrade Open WebUI to version 0.3.16 or later to remediate the missing permission check vulnerability
  • Review file access logs for unauthorized enumeration, access, or deletion activity by non-owner accounts
  • Validate that file-related API endpoints enforce ownership-based access controls after patching
  • Consider implementing additional authorization logging for file operations in self-hosted AI platforms
  • Assess whether sensitive files uploaded to the platform require integrity verification or backup restoration

Evidence notes

Vulnerability confirmed through GitHub Security Advisory GHSA-r8wh-8m7r-fh33 with vendor-supplied fix in version 0.3.16. CVSS 3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N supports HIGH severity rating. CPE criteria confirms affected versions exclude 0.3.16 and later.

Official resources

2026-05-15