CVE-2026-109284

Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/open-webui/open-webui/security/advisories/GHSA-6fjc-5cg3-mgvh
https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-improper-authorization-via-chat-fork-endpoint

Configurations

No configuration.

History

12 Oct 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-12 17:17

Updated : 2026-10-13 20:39

NVD link : CVE-2026-109284

Mitre link : CVE-2026-109284

CVE.ORG link : CVE-2026-109284

JSON object : View

Products Affected

No product.

CWE

CWE-862

Missing Authorization

{"id": "CVE-2026-109284", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-109284", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-13T15:49:10.630395Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "open-webui", "product": "open-webui", "versions": [{"status": "affected", "version": "0.11.0", "lessThan": "0.11.4", "versionType": "semver"}, {"status": "unaffected", "version": "0.11.4", "versionType": "semver"}], "packageURL": "pkg:pypi/open-webui", "defaultStatus": "unaffected"}]}], "published": "2026-10-12T17:17:21.317", "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-6fjc-5cg3-mgvh", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-improper-authorization-via-chat-fork-endpoint", "source": "disclosure@vulncheck.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-862"}]}], "descriptions": [{"lang": "en", "value": "Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members."}], "lastModified": "2026-10-13T20:39:48.767", "sourceIdentifier": "disclosure@vulncheck.com"}