CVE-2026-70493
📛 CVE Title
Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically
Description
Open 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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 6.5 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H- Effective score
- 6.5 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-1333 - Reserved
- 2026-08-04
- Published
- 2026-08-04 20:56 UTC
- Last updated
- 2026-08-04 20:56 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/70xxx/CVE-2026-70493.json
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| open-webui | open-webui |
>= 0.9.6, < 0.11.0 (affected)
|
— |
Vendor references (4)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6 x_refsource_CONFIRM
- https://github.com/open-webui/open-webui/pull/27471 x_refsource_MISC
- https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595 x_refsource_MISC
- https://github.com/open-webui/open-webui/releases/tag/v0.11.0 x_refsource_MISC
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-70493.json.
{
"containers": {
"cna": {
"affected": [
{
"product": "open-webui",
"vendor": "open-webui",
"versions": [
{
"status": "affected",
"version": ">= 0.9.6, < 0.11.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Open 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."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-1333",
"description": "CWE-1333: Inefficient Regular Expression Complexity",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-04T20:56:20.541Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6"
},
{
"name": "https://github.com/open-webui/open-webui/pull/27471",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/open-webui/open-webui/pull/27471"
},
{
"name": "https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595"
},
{
"name": "https://github.com/open-webui/open-webui/releases/tag/v0.11.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.0"
}
],
"source": {
"advisory": "GHSA-2f54-p244-32q6",
"discovery": "UNKNOWN"
},
"title": "Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-70493",
"datePublished": "2026-08-04T20:56:20.541Z",
"dateReserved": "2026-08-04T15:24:41.340Z",
"dateUpdated": "2026-08-04T20:56:20.541Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}