open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.
CVE-2026-56400
HIGHPre-NVD 8.38.3—Trending — 3 sources updated this weekElevated
EchelonGraph scoreHIGH confidence
Score 8.3 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-15. a secondary CVSS source baseline 8.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
8.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 8.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.3
- EG Score
- 8.3(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 - Remote Code Execution via CORS Misconfiguration and Session Validation | Advisories | VulnCheck
https://www.vulncheck.com/advisories/open-webui-remote-code-execution-via-cors-misconfiguration-and-session-validationgithub Patch Available🟡 PoC Available
GitHub Security Lab (GHSL) Vulnerability Report, open-webui: GHSL-2024-174, GHSL-2024-175 · Advisory · open-webui/open-webui · GitHub
https://github.com/open-webui/open-webui/security/advisories/GHSA-6xcp-7mpr-m7wmVendor Advisories for CVE-2026-56400(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.
- 2026-07-16 00:57 UTCEG score recompute
- 2026-07-16 00:57 UTCGHSA enrichment
- 2026-07-15 11:55 UTCEG score recompute
- 2026-07-15 11:54 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-56400?
CVE-2026-56400 is a high vulnerability published on July 15, 2026. open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests…
When was CVE-2026-56400 disclosed?
CVE-2026-56400 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-2026-56400?
CVE-2026-56400 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-56400?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56400, 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-2026-56400
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