CVE-2025-4166 Vault May Include Sensitive Data in Error Logs When Using the KV v2 Plugin

What is CVE-2025-4166?

CVE-2025-4166 is a medium-severity vulnerability in Hashicorp Vault, published on 2 May 2025. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-209

Which versions are affected by CVE-2025-4166?

5 open source packages ship an affected version, including github.com/hashicorp/vault, openbao and vault. It affects 2 products.

Products include Hashicorp Vault, Openbao Openbao.

How do I fix CVE-2025-4166?

Upgrade github.com/hashicorp/vault to 1.19.3 or later.

Is CVE-2025-4166 being exploited?

There is no known exploitation of CVE-2025-4166 in the wild and no public exploit code.

Other vulnerabilities in Hashicorp Vault

• CVE-2020-35192 Hardcoded credentials in n/a Critical 9.8
• CVE-2020-12757 Improper Input Validation in HashiCorp Vault Critical 9.8
• CVE-2025-6000 Arbitrary Remote Code Execution via Plugin Catalog Abuse Critical 9.1
• CVE-2022-40186 HashiCorp Vault vulnerable to incorrect metadata access Critical 9.1
• CVE-2022-36129 Missing authorization in n/a Critical 9.1

All Hashicorp Vault vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-openbao-2025-4166, BIT-vault-2025-4166, GHSA-gcqf-f89c-68hv, GO-2025-3663, openSUSE-SU-2025:15186-1.