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
CRITICALNVD 9.68.3▼Trending — 3 sources updated this weekElevated
EchelonGraph scoreMEDIUM confidence
Score 8.3 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-15. NVD baseline CVSS 9.6; sources differ by 1.3.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.6
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.6Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.6
- EG Score
- 8.3(medium)
- EG Risk
- —
- EPSS
- 20.3%
- 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 - 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.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| open-webui | 0.1.124 ... 0.3.9 (51 versions) | 0.3.33 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 14× 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.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-17 03:02 UTCGHSA enrichment
- 2026-07-16 20:23 UTCNVD updateCVSS v3 → 9.6 · severity → CRITICAL
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-16 14:00 UTCGHSA enrichment
- 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(5)
What is CVE-2026-56400?
CVE-2026-56400 is a critical 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, 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-2026-56400 actively exploited?
CVE-2026-56400 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56400?
CVE-2026-56400 has a CVSS v3 base score of 9.6 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.3.
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
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-56400
Is Your Infrastructure Affected by CVE-2026-56400?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.