Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, when setting model permissions so that a group has read access to it, intending for other users to use it, those users also can read the model's system prompt. However users may consider their system prompt confidential, so this is considered a security issue. This vulnerability is fixed in 0.9.5.
CVE-2026-45387
MEDIUMNVD 4.34.3—Elevated
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 4.3 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.3
- EG Score
- 4.3(medium)
- EPSS
- 12.4%
- KEV
- Not listed
Published
May 15, 2026
Last Modified
May 19, 2026
Advisory Details (1)
Auto-updated Jun 17, 2026🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available
Sharing models for others to use (read permission) also exposes model details (system prompt leakage) · Advisory · open-webui/open-webui · GitHub
https://github.com/open-webui/open-webui/security/advisories/GHSA-h2cw-7qw9-56xrVendor Advisories for CVE-2026-45387(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.
Frequently asked(5)
What is CVE-2026-45387?
CVE-2026-45387 is a medium vulnerability published on May 15, 2026. Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, when setting model permissions so that a group has read access to it, intending for other users to use it, those users also can read the model's system prompt. However users may…
When was CVE-2026-45387 disclosed?
CVE-2026-45387 was first published in the National Vulnerability Database on May 15, 2026, with the most recent update on May 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45387 actively exploited?
CVE-2026-45387 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45387?
CVE-2026-45387 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-45387?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45387, 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-2026-45387
Is Your Infrastructure Affected by CVE-2026-45387?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.