CVE-2026-4525

Modified Modified - Updated After Analysis

Authorization Header Token Disclosure in HashiCorp Vault Auth Mount

Publication date: 2026-04-17

Last updated on: 2026-06-30

Assigner: HashiCorp Inc.

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-04-17

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-04-17

EPSS Evaluated

2026-07-05

NVD

CVE-2026-4525

EUVD

EUVD-2026-23345

Affected Vendors & Products

Vendor	Product	Version / Range
hashicorp	vault	From 1.20.0 (inc) to 1.20.10 (exc)
hashicorp	vault	From 1.21.0 (inc) to 1.21.5 (exc)
hashicorp	vault	From 0.11.2 (inc) to 2.0.0 (exc)
hashicorp	vault	From 0.11.2 (inc) to 1.19.16 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-201	The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

Attack-Flow Graph

Executive Summary

This vulnerability occurs when a Vault authentication mount is configured to pass through the "Authorization" header, and that header is used to authenticate to Vault. In this case, Vault mistakenly forwards the Vault token contained in the "Authorization" header to the authentication plugin backend.

Impact Analysis

The vulnerability can lead to unauthorized disclosure of Vault tokens because the tokens are forwarded to the authentication plugin backend. This could allow attackers or unauthorized parties to gain access to sensitive Vault tokens, potentially compromising confidentiality, integrity, and availability of secrets managed by Vault.

Mitigation Strategies

To mitigate this vulnerability, upgrade Vault to one of the fixed versions: 2.0.0, 1.21.5, 1.20.10, or 1.19.16.

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