cve.bz

CVE-2026-56398

8.5 highEPSS 0.6%

High (8.5) in openwebui open webui. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in open-webui 0.9.5.

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.

Severity

CVSS 4.0

8.5 high
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

CVSS 3.1

9.0 critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
EPSS
0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-31)
CWE
CWE-20
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-3wgj-c2hg-vm6qPyPIopen-webui<0.9.50.9.5

References

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