CVE-2026-44552Network attack vector

Cross-instance cache poisoning via unprefixed Redis keys

Published May 15, 2026 · Updated May 15, 2026

Cache isolation failure in Open WebUI before 0.9.0 allows remote authenticated users to poison another instance's tool configuration. Redis operations in utils/tools.py store and retrieve tool_servers and terminal_servers under bare keys instead of REDIS_KEY_PREFIX-scoped keys. Exploitation requires administrative access to one of multiple instances sharing Redis and exposes another instance's users to attacker-selected tool endpoints, data disclosure, and injected tool output.

CVSS severity8.7
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cache isolation failure in Open WebUI before 0.9.0 allows remote authenticated users to poison another instance's tool configuration. Redis operations in utils/tools.py store and retrieve tool_servers and terminal_servers under bare keys instead of REDIS_KEY_PREFIX-scoped keys. Exploitation requires administrative access to one of multiple instances sharing Redis and exposes another instance's users to attacker-selected tool endpoints, data disclosure, and injected tool output.

The record

CVE
CVE-2026-44552
Published
May 15, 2026
Updated
May 15, 2026
Vendor
Open WebUI
Product
Open WebUI
Classifications
CWE-668
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 15, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=< 0.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Open WebUI · Open WebUIversion=< 0.9.0

Published CVSS scores

8.7GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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