Security Bulletin
Summary
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.
Vulnerability Details
CVEID: CVE-2026-4525
DESCRIPTION: Due to a flaw in the request processing logic, Vault did not strip the Vault token from the forwarded header. Vault will now strip the Vault token used in the request to the auth plugin backends when making a request, even if the auth method is configured to pass through the header.
CWE: CWE-201: Insertion of Sensitive Information Into Sent Data
CVSS Source: HashiCorp Inc.
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Vault Community Edition | affected from 0.11.2 up to 2.0.0 |
| Vault Enterprise | affected from 0.11.2 up to 2.0.0, unaffected from 1.19.16, 1.20.10, 1.21.5 |
Remediation/Fixes
Customers should evaluate the risk associated with this issue and consider upgrading to Vault Community Edition 2.0.0 or Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16. Please refer to Upgrading Vault for general guidance.
Get Notified about Future Security Bulletins
References
Link to HashiCorp Security Bulletin: https://discuss.hashicorp.com/t/hcsec-2026-07-vault-may-expose-tokens-to-auth-plugins-due-to-incorrect-header-sanitization/77344
Acknowledgement
This issue was identified and reported by Oleh Konko of 1seal.
Change History
16 Apr 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
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Document Location
Worldwide
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Document Information
Modified date:
12 May 2026
Initial Publish date:
16 April 2026
UID
ibm17269895