Vulnerability in Vantage6

CVE-2025-43866

vantage6 is an open-source infrastructure for privacy preserving analysis. The JWT secret key in the vantage6 server is auto-generated unless defined by the user. The auto-generated key is a UUID1, which is not cryptographically secure as it is predictable to some extent. This vulnerability is fixed in 4.11.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-43866: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-43866?
CVE-2025-43866 is a high-severity vulnerability in Vantage6, classified under Use of Insufficiently Random Values. CVSS score: 7.5/10. Published 2025-06-12.
How severe is CVE-2025-43866?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-43866 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.