CVE-2026-5052
Received Received - Intake
ACME Validation Bypass in Vault PKI Causes Information Disclosure

Publication date: 2026-04-17

Last updated on: 2026-04-27

Assigner: HashiCorp Inc.

Description
Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challenges. This may lead to these requests being sent to local network targets, potentially leading to information disclosure. Fixed in Vault Community Edition 2.0.0 and Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16.
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Meta Information
Published
2026-04-17
Last Modified
2026-04-27
Generated
2026-06-16
AI Q&A
2026-04-17
EPSS Evaluated
2026-06-15
NVD
CVE-2026-5052
EUVD
EUVD-2026-23344
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
hashicorp vault From 1.14.0 (inc) to 2.0.0 (exc)
hashicorp vault From 1.14.0 (inc) to 1.19.16 (exc)
hashicorp vault From 1.20.0 (inc) to 1.20.10 (exc)
hashicorp vault From 1.21.0 (inc) to 1.21.5 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
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Executive Summary

Vault's PKI engine's ACME validation did not properly reject local targets when issuing http-01 and tls-alpn-01 challenges.

As a result, requests intended for certificate validation could be sent to local network targets instead of the intended external targets.

This behavior could potentially lead to information disclosure.

Impact Analysis

This vulnerability may lead to information disclosure by sending validation requests to unintended local network targets.

An attacker could exploit this to gain access to sensitive information within the local network.

The CVSS base score of 5.3 indicates a medium severity impact with no required privileges or user interaction.

Mitigation Strategies

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

Compliance Impact

The vulnerability in Vault’s PKI engine could potentially lead to information disclosure by sending ACME validation requests to local network targets. Such information disclosure risks may impact compliance with data protection standards and regulations like GDPR and HIPAA, which require safeguarding sensitive information against unauthorized access or exposure.

However, the provided information does not explicitly detail the direct effects on compliance with these standards or regulations.

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