CVE-2026-56400Public exploitNetwork attack vector

Remote code execution via credentialed cross-origin requests

Published Jul 15, 2026 · Updated Jul 15, 2026

CORS and session flaws in Open WebUI before 0.3.14 allow remote attackers to execute code through an administrator's browser. Multiple FastAPI routers configure CORSMiddleware with wildcard origins and credentials, while logout leaves reusable session cookies; authenticated cross-site requests to /api/v1/functions can create and enable attacker-supplied Python. Exploitation requires an administrator to visit and interact with an attacker-controlled page, after which code runs with the Open WebUI service's privileges.

CVSS severity9.0
Critical
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CORS and session flaws in Open WebUI before 0.3.14 allow remote attackers to execute code through an administrator's browser. Multiple FastAPI routers configure CORSMiddleware with wildcard origins and credentials, while logout leaves reusable session cookies; authenticated cross-site requests to /api/v1/functions can create and enable attacker-supplied Python. Exploitation requires an administrator to visit and interact with an attacker-controlled page, after which code runs with the Open WebUI service's privileges.

The record

CVE
CVE-2026-56400
Published
Jul 15, 2026
Updated
Jul 15, 2026
Vendor
Open WebUI
Product
Open WebUI
Classifications
CWE-613, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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 <0.3.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open WebUI · Open WebUIversion=0 <0.3.14

Published CVSS scores

9.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
9.0VulnCheckCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.3VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-613Insufficient Session Expiration
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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