CVE-2026-56398: high-severity vulnerability in open-webui
Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.5epss 0.6%
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.
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
Affected products
open-webui · open-webuiRelated CVEs — open-webui
In the same product, most dangerous first.
CVE-2025-64496HIGHOpen WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE EventsEPSS 7.2%CVE-2026-34222HIGHOpen WebUI has Broken Access Control in Tool ValvesEPSS 5.1%CVE-2025-65958HIGHOpen WebUI vulnerable to Server-Side Request Forgery (SSRF) via Arbitrary URL Processing in /api/v1/retrieval/process/webEPSS 4.7%CVE-2026-28788HIGHOpen WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwriteEPSS 3.0%CVE-2026-44551CRITICALOpen WebUI: LDAP Empty Password Authentication BypassEPSS 1.5%CVE-2026-45397MEDIUMOpen WebUI: Unauthenticated RAG Configuration DisclosureEPSS 0.8%