CVE-2025-43866Network attack vector

Token forgery via predictable UUID1 signing secret

Published Jun 12, 2025 · Updated Jun 13, 2025

Insufficient randomness in vantage6 Server before 4.11 allows remote attackers to predict an auto-generated JWT signing secret. When jwt_secret_key is absent from the server configuration, startup generates the signing key with UUID1, encoding time and host-derived data rather than cryptographic randomness. Exploitation requires predicting the generated value; a recovered key permits forged access tokens and unauthorized API access.

CVSS severity7.5
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient randomness in vantage6 Server before 4.11 allows remote attackers to predict an auto-generated JWT signing secret. When jwt_secret_key is absent from the server configuration, startup generates the signing key with UUID1, encoding time and host-derived data rather than cryptographic randomness. Exploitation requires predicting the generated value; a recovered key permits forged access tokens and unauthorized API access.

The record

CVE
CVE-2025-43866
Published
Jun 12, 2025
Updated
Jun 13, 2025
Vendor
vantage6
Product
vantage6
Classifications
CWE-330, T1606
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

vantage6 · vantage6version=< 4.11

Published CVSS scores

1.7GitHub, Inc.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
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1606Forge Web Credentials

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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