CVE-2026-5052
ACME Validation Bypass in Vault PKI Causes Information Disclosure
Publication date: 2026-04-17
Last updated on: 2026-04-27
Assigner: HashiCorp Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| 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 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
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.
How can this vulnerability impact me? :
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.
What immediate steps should I take to mitigate this vulnerability?
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.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
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.