{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-109300", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-12T14:13:39.026Z", "datePublished": "2026-10-12T16:04:58.200Z", "dateUpdated": "2026-10-13T18:09:47.634Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-12T16:04:58.200Z"}, "datePublic": "2026-09-27T00:00:00.000Z", "title": "Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds", "descriptions": [{"lang": "en", "value": "Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "cweId": "CWE-79", "type": "CWE"}]}], "affected": [{"vendor": "open-webui", "product": "open-webui", "defaultStatus": "unaffected", "packageURL": "pkg:pypi/open-webui", "versions": [{"version": "0.6.31", "status": "affected", "versionType": "semver", "lessThan": "0.11.4"}, {"version": "0.11.4", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*", "versionStartIncluding": "0.6.31", "versionEndExcluding": "0.11.4"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 5.1, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 4.6, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-9wj4-mcm3-ppj6)"}, {"name": "VulnCheck Advisory: Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds"}], "credits": [{"lang": "en", "value": "KadirArslan", "type": "reporter"}, {"lang": "en", "value": "5yu4n", "type": "reporter"}, {"lang": "en", "value": "Classic298", "type": "coordinator"}], "x_generator": {"engine": "vulncheck-endgame"}}, "adp": [{"references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-10-13T18:09:25.448143Z", "id": "CVE-2026-109300", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-13T18:09:47.634Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-109300", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-13T18:09:25.448143Z"}}}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-13T18:09:42.783Z"}}], "cna": {"title": "Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds", "credits": [{"lang": "en", "type": "reporter", "value": "KadirArslan"}, {"lang": "en", "type": "reporter", "value": "5yu4n"}, {"lang": "en", "type": "coordinator", "value": "Classic298"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "baseScore": 5.1, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "userInteraction": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "LOW"}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.6, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}}], "affected": [{"vendor": "open-webui", "product": "open-webui", "versions": [{"status": "affected", "version": "0.6.31", "lessThan": "0.11.4", "versionType": "semver"}, {"status": "unaffected", "version": "0.11.4", "versionType": "semver"}], "packageURL": "pkg:pypi/open-webui", "defaultStatus": "unaffected"}], "datePublic": "2026-09-27T00:00:00.000Z", "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6", "name": "GitHub Security Advisory (GHSA-9wj4-mcm3-ppj6)", "tags": ["vendor-advisory"]}, {"url": "https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds", "name": "VulnCheck Advisory: Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds", "tags": ["third-party-advisory"]}], "x_generator": {"engine": "vulncheck-endgame"}, "descriptions": [{"lang": "en", "value": "Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-79", "description": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "0.11.4", "versionStartIncluding": "0.6.31"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-12T16:04:58.200Z"}}}, "cveMetadata": {"cveId": "CVE-2026-109300", "state": "PUBLISHED", "dateUpdated": "2026-10-13T18:09:47.634Z", "dateReserved": "2026-10-12T14:13:39.026Z", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "datePublished": "2026-10-12T16:04:58.200Z", "assignerShortName": "VulnCheck"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:pypi/open-webui", "product": "open-webui", "vendor": "open-webui", "versions": [{"lessThan": "0.11.4", "status": "affected", "version": "0.6.31", "versionType": "semver"}, {"status": "unaffected", "version": "0.11.4", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled."}], "id": "CVE-2026-109300", "lastModified": "2026-10-15T15:55:45.630", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.6, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.1, "impactScore": 2.5, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.1, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-109300", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-13T18:09:25.448143Z", "version": "2.0.3"}}]}, "published": "2026-10-12T17:17:23.700", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0.6.31,0.11.4)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "0.11.4"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "open-webui", "source": "cna", "vendor": "open-webui"}, "product": "open_webui", "vendor": "openwebui"}], "created": "2026-10-12T18:00:03.803079+00:00", "updated": "2026-10-13T05:30:17.419097+00:00", "vendors": ["openwebui", "openwebui$PRODUCT$open_webui"]}