What is CVE-2026-56399?

CVE-2026-56399 is a medium-severity vulnerability in Open-Webui, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.0/10. Published 2026-06-30.

How severe is CVE-2026-56399?

Medium severity. CVSS v3 base score is 5.0 out of 10.

SSRF in Open-Webui

CVE-2026-56399

Open WebUI before 0.6.27 contains a server-side request forgery vulnerability in the /api/v1/retrieval/process/web endpoint that allows authenticated users to bypass SSRF protections. Attackers can manipulate URL parameters with location redirect headers to access internal services and potentially execute commands via instance secrets.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.003 (24.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N.

Affected products

Open-webui — versions 0, 0.6.27

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-56399?: CVE-2026-56399 is a medium-severity vulnerability in Open-Webui, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.0/10. Published 2026-06-30.
How severe is CVE-2026-56399?: Medium severity. CVSS v3 base score is 5.0 out of 10.