CVE-2026-88021: Hashicorp Consul

High severity, CVSS 7.1. EPSS: 0.3% chance of exploitation in the next 30 days.

Consul and Consul Enterprise are vulnerable to an authorization bypass in the Connect service mesh that may allow a service to reach a destination it is not authorized to access. When building Envoy RBAC rules to enforce Connect intentions, Consul did not correctly escape certain characters in service names, namespaces, and partitions, causing the generated authorization rules to match more broadly than intended. This vulnerability (CVE-2026-88021) is fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12 and 2.0.4.

Affected products

• Hashicorp Consul: from 1.9.0, before 2.0.4 (fixed in 2.0.4)
• Hashicorp Consul Enterprise: from 1.9.0, before 2.0.4 (fixed in 2.0.4)

Published 2026-09-10. Last modified 2026-09-10.