OpenBao prior 2.6.0 Policy Templating input validation

Summaryinfo

A vulnerability described as problematic has been identified in OpenBao prior 2.6.0. The impacted element is an unknown function of the component Policy Templating. Such manipulation leads to input validation. This vulnerability is referenced as CVE-2026-71543. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in OpenBao prior 2.6.0. It has been rated as problematic. Affected by this issue is an unknown code block of the component Policy Templating. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. CVE summarizes:

OpenBao is an open source identity-based secrets management system. Prior to 2.6.0, templated ACL, PKI, and SSH policies could substitute attacker-controlled identity data without rejecting syntax-significant characters. In ACL templated policies, asterisks, plus signs, and slashes could alter path matching. In PKI allowed_uri_sans_template and allowed_domains policies, an asterisk could broaden certificate issuance to unauthorized domains. In SSH allowed_users and allowed_domains policies, a comma could add unauthorized principals. Exploitation requires a deployment to use templated policy data that users can freely modify; templates based on the randomly generated identity.entity.id value are not affected. This could allow privilege escalation, unauthorized access, and unauthorized certificate issuance. This issue is fixed in version 2.6.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-71543 since 08/06/2026. The exploitation is known to be easy. The attack may be launched remotely. The exploitation requires an enhanced level of successful authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/21/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-83955). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• OpenBao

Version

• <2.6.0

Website

• Product: https://github.com/openbao/openbao/

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Once again VulDB remains the best source for vulnerability data.

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