{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-56398","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-06-21T12:37:58.435Z","datePublished":"2026-07-15T11:25:30.722Z","dateUpdated":"2026-07-15T13:25:55.678Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-07-15T11:25:30.722Z"},"datePublic":"2026-05-10T00:00:00.000Z","title":"Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI","descriptions":[{"lang":"en","value":"Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs. Authenticated users who visit the profile image endpoint receive attacker-controlled SVG content with inline disposition and no default security headers, enabling script execution in the same origin to steal authentication tokens and achieve account takeover."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Input Validation","cweId":"CWE-20","type":"CWE"}]}],"affected":[{"vendor":"open-webui","product":"open-webui","defaultStatus":"unaffected","packageURL":"pkg:pypi/open-webui","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"0.9.5"},{"version":"0.9.5","status":"unaffected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*","versionEndExcluding":"0.9.5"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.5,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":7.3,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-3wgj-c2hg-vm6q","name":"GitHub Security Advisory (GHSA-3wgj-c2hg-vm6q)","tags":["vendor-advisory"]},{"name":"VulnCheck Advisory: Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/open-webui-stored-cross-site-scripting-via-oauth-picture-claim-svg-data-uri"}],"credits":[{"lang":"en","value":"matte1782","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T13:20:08.460857Z","id":"CVE-2026-56398","options":[{"Exploitation":"none"},{"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":"2026-07-15T13:25:55.678Z"}}]}}