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VaultApplication · Hashicorp

CVE-2026-4525

HIGH · 8.8 CVSS v3.1 Published 2026-04-17
Fix available
A fix is available. Upgrade to 1.19.16 / 1.20.10 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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
If a Vault auth mount is configured to pass through the "Authorization" header, and the "Authorization" header is used to authenticate to Vault, Vault forwarded the Vault token to the auth plugin backend. Fixed in 2.0.0, 1.21.5, 1.20.10, and 1.19.16.

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

When a Vault auth mount is configured to pass through the 'Authorization' header and that header is used for authentication, Vault incorrectly forwards the obtained Vault token to the auth plugin backend. This causes token leakage to external auth plugins, potentially allowing plugin operators to hijack the token and access Vault resources.

MitigationUpgrade Vault to version 2.0.0, 1.21.5, 1.20.10, or 1.19.16. Review auth mount configurations to remove unnecessary Authorization header passthrough and audit for any token misuse.

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:>= 0.11.2, < 1.19.16>= 0.11.2, < 2.0.0>= 1.20.0, < 1.20.10>= 1.21.0, < 1.21.5

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Check installed Vault version
    Run `vault version` or check the Vault binary version
    Affected if The installed version falls within the affected ranges: < 1.19.16, < 2.0.0, 1.20.0-1.20.10, or 1.21.0-1.21.5
  2. List all authentication mounts
    Run `vault auth list -detailed` or query the `sys/auth` endpoint via API
    Affected if Any authentication mount exists on the Vault instance
  3. Inspect auth mount header pass-through configuration
    For each auth mount, query `sys/auth/<mount-point>/config` or run `vault read sys/auth/<mount-point>/config` and check for `passthrough_request_headers` or `allowed_request_headers` options
    Affected if An auth mount has `passthrough_request_headers` or `allowed_request_headers` configured to include the 'Authorization' header
  4. Verify if Authorization header is used for authentication
    Review authentication requests or audit logs to determine if clients are authenticating using the 'Authorization' header with a Bearer token
    Affected if The Authorization header is being used as an authentication method against Vault while the affected mount configuration exists

A user is affected if they run an affected Vault version, have an auth mount configured with Authorization header pass-through enabled, and clients authenticate using the Authorization header, resulting in the Vault token being forwarded to the auth backend.

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 1.19.16 / 1.20.10 / 1.21.5 or later
Fixed in 1.19.161.20.101.21.5
Interim mitigation

Upgrade Vault to version 2.0.0, 1.21.5, 1.20.10, or 1.19.16. Review auth mount configurations to remove unnecessary Authorization header passthrough and audit for any token misuse.

Recommended fix High confidence

1.19.16, 1.20.10, 1.21.5, or 2.0.0 (latest stable)

  1. Identify the current Vault version using `vault version`
  2. Determine the target upgrade version based on your current major version: if on 1.19.x upgrade to 1.19.16, if on 1.20.x upgrade to 1.20.10, if on 1.21.x upgrade to 1.21.5, or upgrade to 2.0.0 for the latest major release
  3. Review the Vault upgrade guide at https://developer.hashicorp.com/vault/docs/upgrading
  4. Ensure you have a tested backup and snapshot of your Vault data
  5. Stop the Vault service before upgrading
  6. Upgrade the Vault binary to the target version
  7. Verify the new version with `vault version`
  8. Start the Vault service
Caveat Review HashiCorp Vault upgrade guides for any known issues between your current version and target version; minor version upgrades typically have minimal breaking changes

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

Fix this in Vault Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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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-2026-4525 in production — separate from our analysis above.

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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