Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-70493
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-04 21:16:38 UTC
Updated2026-08-04 21:16:38 UTC
DescriptionOpen WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file with no time limit, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affected worker. This issue is fixed in 0.11.0.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-1333 | CWE-1333 CWE-1333: Inefficient Regular Expression Complexity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Open-webui Open-webui affected >= 0.9.6, < 0.11.0 Not specified

References

ReferenceSourceLinkTags
github.com/open-webui/open-webui/pull/27471 [email protected] github.com
github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6 [email protected] github.com
github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9c... [email protected] github.com
github.com/open-webui/open-webui/releases/tag/v0.11.0 [email protected] github.com
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