How severe is CVE-2025-43866?

CVE-2025-43866 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2025-43866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-43866?

CVE-2025-43866 affects Vantage6. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-43866?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-43866 have an EU (EUVD) identifier?

Yes. CVE-2025-43866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18201.

When was CVE-2025-43866 published?

CVE-2025-43866 was published on 2025-06-12 and last updated on 2026-06-17.

CVE-2025-43866

CVE-2025-43866 is a high-severity vulnerability in Vantage6 with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-330.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 1.7
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-18201
Weakness: CWE-330
Affected product: Vantage6
Published: 2025-06-12
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-43866?: CVE-2025-43866 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2025-43866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-43866?: CVE-2025-43866 affects Vantage6. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-43866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-43866 have an EU (EUVD) identifier?: Yes. CVE-2025-43866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18201.
When was CVE-2025-43866 published?: CVE-2025-43866 was published on 2025-06-12 and last updated on 2026-06-17.

References

https://github.com/vantage6/vantage6/security/advisories/GHSA-m3mq-f375-5vgh

Affected products (1)

cpe:2.3:a:vantage6:vantage6:*:*:*:*:*:*:*:*

More vulnerabilities in Vantage6

CVE-2025-43863 — Critical (CVSS 9.8): vantage6 is an open source framework built to enable, manage and deploy privacy enhancing technologies like Federated…
CVE-2024-21649 — High (CVSS 8.8): The vantage6 technology enables to manage and deploy privacy enhancing technologies like Federated Learning (FL) and…
CVE-2023-23929 — High (CVSS 8.8): vantage6 is a privacy preserving federated learning infrastructure for secure insight exchange. Currently, the refresh…
CVE-2023-47631 — High (CVSS 7.2): vantage6 is a framework to manage and deploy privacy enhancing technologies like Federated Learning (FL) and…
CVE-2024-21653 — Medium (CVSS 6.5): The vantage6 technology enables to manage and deploy privacy enhancing technologies like Federated Learning (FL) and…
CVE-2023-22738 — Medium (CVSS 6.3): vantage6 is a privacy preserving federated learning infrastructure for secure insight exchange. Assigning existing…

All CVEs affecting Vantage6 →

Other CWE-330 (Use of Insufficiently Random Values) vulnerabilities

CVE-2023-22601 — Critical (CVSS 10.0): InHand Networks InRouter 302, prior to version IR302 V3.5.56, and InRouter 615, prior to version…
CVE-2026-25072 — Critical (CVSS 9.8): XikeStor SKS8310-8X Network Switch firmware versions 1.04.B07 and prior contain a predictable session identifier…
CVE-2026-27755 — Critical (CVSS 9.8): SODOLA SL902-SWTGW124AS firmware versions through 200.1.20 contain a weak session identifier generation vulnerability…
CVE-2026-27637 — Critical (CVSS 9.8): FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.206,…
CVE-2025-64097 — Critical (CVSS 9.8): NervesHub is a web service that allows users to manage over-the-air (OTA) firmware updates of devices in the field. A…
CVE-2025-4607 — Critical (CVSS 9.8): The PSW Front-end Login & Registration plugin for WordPress is vulnerable to Privilege Escalation in all versions up…

Browse all CWE-330 (Use of Insufficiently Random Values) vulnerabilities →