What is CVE-2026-56398?

CVE-2026-56398 is a high-severity vulnerability in Open-webui, classified under Improper Input Validation. CVSS score: 7.3/10. Published 2026-07-15.

How severe is CVE-2026-56398?

High severity. CVSS v3 base score is 7.3 out of 10.

Improper input validation in Open-webui

CVE-2026-56398

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 bypa…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N.

Affected products

Open-webui — versions 0, 0.9.5

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-56398?: CVE-2026-56398 is a high-severity vulnerability in Open-webui, classified under Improper Input Validation. CVSS score: 7.3/10. Published 2026-07-15.
How severe is CVE-2026-56398?: High severity. CVSS v3 base score is 7.3 out of 10.