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VaultApplication · Hashicorp

CVE-2025-4166

MEDIUM · 6.5 CVSS v3.1 Published 2025-05-02
Fix available
A fix is available. Upgrade to 1.16.20 / 1.17.16 or later.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Vault Community and Vault Enterprise Key/Value (kv) Version 2 plugin may unintentionally expose sensitive information in server and audit logs when users submit malformed payloads during secret creation or update operations via the Vault REST API. This vulnerability, identified as CVE-2025-4166, is fixed in Vault Community 1.19.3 and Vault Enterprise 1.19.3, 1.18.9, 1.17.16, 1.16.20.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Vault KV v2 plugin incorrectly logs sensitive information from secret payloads to server and audit logs when users submit malformed requests during secret creation or update via the REST API, leading to potential credential exposure.

MitigationUpgrade to Vault Community 1.19.3 or Enterprise 1.19.3/1.18.9/1.17.16/1.16.20, and conduct a retrospective audit of existing server and audit logs to identify and remediate any previously leaked sensitive data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
VaultApplication
Affected:>= 0.3.0, < 1.16.20>= 0.3.0, < 1.19.3>= 1.17.0, < 1.17.16>= 1.18.0, < 1.18.9>= 1.19.0, < 1.19.3
OpenbaoApplication
Affected:< 2.2.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Vault or Openbao installation version
    Run `vault version` for Vault or `bao version` for Openbao to get the installed version number
    Affected if The version falls within any of the affected ranges: Vault < 1.16.20, < 1.17.16, < 1.18.9, or < 1.19.3; Openbao < 2.2.2
  2. Confirm KV v2 secrets engine is enabled
    Run `vault secrets list` or `bao secrets list` and look for a path with type 'kv' and options version '2'
    Affected if A KV v2 secrets engine is enabled on any path
  3. Verify audit logging is configured
    Check audit device status with `vault audit list` or `bao audit list` to see if any audit devices are enabled
    Affected if At least one audit device is enabled (file, syslog, etc.)
  4. Examine server and audit logs for sensitive data in failed requests
    Search logs (typically at /var/log/vault/ or /var/log/bao/) for entries containing secret values or 'key' parameters alongside HTTP 400/500 error responses during KV v2 secret operations
    Affected if Plaintext secret values or sensitive key names appear in server or audit logs accompanying failed secret creation/update attempts via the KV v2 API

A user is affected if they run a vulnerable Vault or Openbao version with KV v2 enabled and have audit logging active, with the additional condition that malformed secret create/update API requests may have leaked sensitive values into their logs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.16.20 / 1.17.16 / 1.18.9 or later
Fixed in 1.16.201.17.161.18.9
Interim mitigation

Upgrade to Vault Community 1.19.3 or Enterprise 1.19.3/1.18.9/1.17.16/1.16.20, and conduct a retrospective audit of existing server and audit logs to identify and remediate any previously leaked sensitive data.

Recommended fix High confidence

Vault 1.16.20+, 1.17.16+, 1.18.9+, 1.19.3+ or OpenBao 2.2.2+

  1. 1. Identify the current Vault or OpenBao version running in your environment
  2. 2. Determine the appropriate upgrade path based on your current version branch
  3. 3. Review the official HashiCorp Vault upgrade documentation for your version
  4. 4. Schedule a maintenance window and create a backup of your Vault data
  5. 5. For Vault 1.16.x: upgrade to 1.16.20 or later
  6. 6. For Vault 1.17.x: upgrade to 1.17.16 or later
  7. 7. For Vault 1.18.x: upgrade to 1.18.9 or later
  8. 8. For Vault 1.19.x: upgrade to 1.19.3 or later
Caveat Standard Vault upgrade considerations apply - review release notes for your version branch for any behavioral changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Vault Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-4166 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data