CVE-2025-43866 json
Vantage6 Server JWT secret not cryptographically secure
published last yr. modified 4mo ago also EUVD-2025-18201 , GHSA-m3mq-f375-5vgh , PYSEC-2025-221
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 34%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2025-43866 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- last yr.
Exploit prediction
0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 1.7 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U |
| CNA | 4.0 | 1.7 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| OSV | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | vantage6-server | <4.11.0 |
4.11.0 |
Affected products
- vantage6 vantage6
Classification
- Weakness
-
- CWE-330 Use of Insufficiently Random Values
References
-
github.com
/vantage6/vantage6/commit/e39a262faf1cd4c554bf1b8e57eeea082da995c0
web
-
github.com
/vantage6/vantage6/security/advisories/GHSA-m3mq-f375-5vgh
web, vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2025-43866
advisory
-
github.com
/pypa/advisory-database/tree/main/vulns/vantage6-server/PYSEC-2025-221.yaml
web
-
github.com
/vantage6/vantage6
package
Sources
- CVE List CVE-2025-43866
- GitHub Advisory GHSA-m3mq-f375-5vgh
- NVD CVE-2025-43866
- OSV PYSEC-2025-221
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.