CVE-2026-56398

CRITICALNVD 9.07.3▼
EchelonGraph scoreMEDIUM confidence

Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-07-15. NVD baseline CVSS 9.0; sources differ by 1.7.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
9.0
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.0Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
9.0
EG Score
7.3(medium)
EG Risk
—
EPSS
26.2%
KEV
Not listed

Published

July 15, 2026

Last Modified

July 16, 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-uri
github 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-vm6q

Vendor 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.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
open-webui0.1.124 ... 0.9.4 (156 versions)0.9.5—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 13× 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.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-20 17:08 UTCEPSS rescore
  3. 2026-07-19 14:31 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 02:29 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-16 20:26 UTCGHSA enrichment
  8. 2026-07-16 20:23 UTCNVD updateCVSS v3 → 9 · severity → CRITICAL
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-16 09:36 UTCGHSA enrichment
  11. 2026-07-15 22:45 UTCGHSA enrichment
  12. 2026-07-15 11:55 UTCEG score recompute
  13. 2026-07-15 11:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56398?
CVE-2026-56398 is a critical 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, with the most recent update on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56398 actively exploited?
CVE-2026-56398 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 26.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56398?
CVE-2026-56398 has a CVSS v3 base score of 9.0 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.3.
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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-56398

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