CVE-2025-4656 is a vulnerability identified in HashiCorp Vault, specifically affecting both Vault Community and Enterprise editions prior to version 1.20.0 (and certain patch releases of earlier branches). The issue arises from synchronous access to a remote resource without an enforced timeout during rekey and recovery key operations. This flaw is categorized under CWE-1088, which involves improper handling of synchronous remote resource access leading to potential denial of service (DoS). In this case, a Vault operator can trigger uncontrolled cancellation of these critical cryptographic operations, causing the Vault service to become unavailable. The vulnerability does not impact confidentiality or integrity but affects availability by allowing an attacker or misbehaving operator to disrupt Vault’s key management processes. The CVSS 3.1 base score is 3.1 (low severity), reflecting that exploitation requires network access with high attack complexity, no privileges, and user interaction, and results only in a limited denial of service. No known exploits are currently reported in the wild. The vulnerability has been remediated in Vault Community Edition 1.20.0 and Vault Enterprise versions 1.20.0, 1.19.6, 1.18.11, 1.17.17, and 1.16.22. The affected versions include 1.14.8 and likely other versions before these patches. The root cause is the lack of timeout controls on synchronous remote calls during sensitive cryptographic operations, allowing cancellation to interrupt these processes and cause service disruption.

For European organizations, the impact of CVE-2025-4656 primarily concerns availability of Vault services used for secrets management and cryptographic key operations. Vault is widely used in cloud-native environments, DevOps pipelines, and infrastructure automation, especially in sectors with stringent security requirements such as finance, healthcare, and critical infrastructure. A denial of service in Vault can halt automated credential retrieval, disrupt secure communications, and delay deployment or recovery operations. Although the vulnerability does not expose sensitive data or allow unauthorized access, the operational disruption can lead to downtime, delayed incident response, and increased operational risk. Organizations relying on Vault for high-availability key management may experience service interruptions impacting business continuity. Given the requirement for user interaction and high attack complexity, exploitation is less likely to be automated or widespread but could be leveraged by insider threats or targeted attackers aiming to disrupt operations.

1. Upgrade Vault installations to the patched versions: Community Edition 1.20.0 or Enterprise 1.20.0 (or the respective patch releases for earlier branches). 2. Implement strict operational controls and auditing around Vault operator actions to detect and prevent unauthorized or accidental cancellation of rekey and recovery operations. 3. Employ network segmentation and access controls to limit which users and systems can interact with Vault’s administrative interfaces, reducing risk of exploitation. 4. Monitor Vault logs and metrics for unusual cancellation events or service interruptions related to key management operations. 5. Develop and test incident response procedures to quickly recover Vault availability in case of disruption. 6. Consider deploying Vault in a highly available cluster configuration with failover to minimize impact of single-node disruptions. 7. Educate Vault operators on the risks of cancellation during critical operations and enforce multi-person approval workflows for sensitive actions where feasible.