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.
CVE-2026-56398
HIGHPre-NVD 7.37.3—Trending — 3 sources updated this week
EchelonGraph scoreHIGH confidence
Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-07-15. a secondary CVSS source baseline 7.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
7.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 7.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.3
- EG Score
- 7.3(high)
- EPSS
- —
- KEV
- Not listed
Published
July 15, 2026
Last Modified
July 15, 2026
Advisory Details (2)
Auto-updated Jul 15, 2026🔬 Proof of concept available. Patch available. Sources: github.
generic
Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI | Advisories | VulnCheck
https://www.vulncheck.com/advisories/open-webui-stored-cross-site-scripting-via-oauth-picture-claim-svg-data-urigithub Patch Available🟡 PoC Available
Stored XSS via OAuth picture claim stored as SVG data URI in profile_image_url · Advisory · open-webui/open-webui · GitHub
https://github.com/open-webui/open-webui/security/advisories/GHSA-3wgj-c2hg-vm6qVendor Advisories for CVE-2026-56398(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-15 22:45 UTCEG score recompute
- 2026-07-15 22:45 UTCGHSA enrichment
- 2026-07-15 11:55 UTCEG score recompute
- 2026-07-15 11:54 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-20
- CVE-2002-2444EG 9.8CRITICAL
- CVE-2005-0116NVD 0.0EG 9.0EPSS 99%NONE
- CVE-2002-1359NVD 0.0EG 9.0EPSS 100%NONE
- CVE-2000-0380NVD 0.0EG 9.0EPSS 98%NONE
- CVE-2000-0258EG 7.5EPSS 97%HIGH
- CVE-2004-2771EG 0.0EPSS 93%NONE
- CVE-2002-2443EG 0.0EPSS 93%NONE
- CVE-2002-2433EG 0.0NONE
- CVE-2003-1569EG 0.0NONE
- CVE-2003-1568EG 0.0NONE
Frequently asked(4)
What is CVE-2026-56398?
CVE-2026-56398 is a high vulnerability published on July 15, 2026. 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.…
When was CVE-2026-56398 disclosed?
CVE-2026-56398 was first published in the National Vulnerability Database on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-56398?
CVE-2026-56398 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-56398?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56398, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-56398
Is Your Infrastructure Affected by CVE-2026-56398?
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