CVE-2026-44552 json
Open WebUI: Redis Cache Keys tool_servers and terminal_servers Missing Instance Prefix Enable Cross-Instance Cache Poisoning
published 2026-05-08 6 mo ago modified 2026-07-13 3 mo ago also GHSA-3x8w-4f7p-xxc2 , PYSEC-2026-2696 , EUVD-2026-30609
- cvss
- 8.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi open-webui 0.9.0
- openwebui open_webui 0.9.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 5 mo ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-3x8w-4f7p-xxc2 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
| OSV | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
| GitHub | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | open-webui | <0.9.0 |
0.9.0 |
Affected products
- open-webui open-webui
Classification
- Weakness
-
- CWE-668 Exposure of Resource to Wrong Sphere
References
-
github.com
/open-webui/open-webui/security/advisories/GHSA-3x8w-4f7p-xxc2
web, exploit, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-44552
advisory
-
github.com
/open-webui/open-webui
package
-
pypi.org
/project/open-webui
package
-
github.com
/advisories/GHSA-3x8w-4f7p-xxc2
advisory
Sources
- CVE List CVE-2026-44552
- GitHub Advisory GHSA-3x8w-4f7p-xxc2
- NVD CVE-2026-44552
- OSV PYSEC-2026-2696
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