CVE-2025-5999 is a high-severity vulnerability identified in HashiCorp Vault, a widely used secrets management tool that securely stores and controls access to tokens, passwords, certificates, and encryption keys. The vulnerability stems from incorrect privilege assignment (CWE-266) within Vault's identity endpoint under the root namespace. Specifically, a privileged Vault operator who already has write permissions to this endpoint can exploit this flaw to escalate their own or another user's token privileges to the Vault root policy level. This escalation effectively grants full administrative control over Vault, enabling unauthorized access to all secrets and sensitive data managed by the system. The vulnerability affects versions including 0.10.4 and was addressed in Vault Community Edition 1.20.0 and Enterprise versions 1.20.0, 1.19.6, 1.18.11, and 1.16.22. The CVSS v3.1 score of 7.2 reflects its high impact, with an attack vector over the network, low attack complexity, requiring high privileges but no user interaction, and resulting in high confidentiality, integrity, and availability impacts. Although no known exploits are currently observed in the wild, the potential for abuse is significant given Vault's critical role in securing infrastructure secrets. The vulnerability highlights a critical trust boundary failure where privileged users can improperly elevate privileges beyond intended limits, undermining the principle of least privilege and potentially leading to full system compromise.

For European organizations, the impact of this vulnerability can be severe. Many enterprises, financial institutions, and government agencies in Europe rely on HashiCorp Vault for managing sensitive credentials and secrets critical to their IT infrastructure and compliance requirements such as GDPR. Exploitation could lead to unauthorized disclosure of confidential data, manipulation or deletion of secrets, and disruption of services dependent on Vault-managed credentials. This could result in regulatory penalties, loss of customer trust, and operational downtime. Furthermore, the ability to escalate privileges to root policy could facilitate lateral movement within networks, enabling attackers to compromise additional systems and data. The risk is particularly acute for organizations with complex multi-tenant environments or those that delegate Vault operator roles without stringent controls. Given the centralized nature of Vault in secret management, a successful attack could have cascading effects across multiple business units and services.

To mitigate this vulnerability, European organizations should immediately upgrade to the patched versions of HashiCorp Vault: Community Edition 1.20.0 or Enterprise versions 1.20.0, 1.19.6, 1.18.11, or 1.16.22. Until upgrades are applied, organizations should restrict write permissions to the root namespace’s identity endpoint to the minimum number of trusted operators and implement strict role-based access controls (RBAC) to enforce the principle of least privilege. Regular audits of Vault operator roles and token privileges should be conducted to detect any anomalous privilege escalations. Additionally, organizations should enable detailed logging and monitoring of Vault API calls related to identity and token management to identify suspicious activities early. Employing multi-factor authentication (MFA) for Vault operators and integrating Vault with centralized security information and event management (SIEM) systems can enhance detection and response capabilities. Finally, organizations should review and update incident response plans to include scenarios involving Vault compromise.