CVE-2026-44552: high-severity vulnerability in open-webui
Open WebUI: Redis Cache Keys tool_servers and terminal_servers Missing Instance Prefix Enable Cross-Instance Cache Poisoning
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.3%
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the tool_servers and terminal_servers keys in utils/tools.py do use a prefix. When two or more Open WebUI instances share a Redis database (a supported and documented deployment pattern, e.g., for multi-region deployments, blue-green setups, or cluster topologies), the unprefixed keys collide. An admin on Instance A writing to tool_servers overwrites the value read by Instance B — causing Instance B's users to receive Instance A's tool server configuration. This vulnerability is fixed in 0.9.0.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
Affected products
open-webui · open-webuiRelated CVEs — open-webui
In the same product, most dangerous first.
CVE-2025-64496HIGHOpen WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE EventsEPSS 7.2%CVE-2026-34222HIGHOpen WebUI has Broken Access Control in Tool ValvesEPSS 5.1%CVE-2025-65958HIGHOpen WebUI vulnerable to Server-Side Request Forgery (SSRF) via Arbitrary URL Processing in /api/v1/retrieval/process/webEPSS 4.4%CVE-2026-28788HIGHOpen WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwriteEPSS 3.0%CVE-2026-44551CRITICALOpen WebUI: LDAP Empty Password Authentication BypassEPSS 1.5%CVE-2026-45397MEDIUMOpen WebUI: Unauthenticated RAG Configuration DisclosureEPSS 0.8%