CVE-2026-88021

Consul vulnerable to an authorization bypass in the Connect service mesh

State: Published
Severity: 7.5 High
Published: Sep 10, 2026
Updated: Oct 2, 2026
Reserved: Sep 9, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N	HashiCorp

Weaknesses

CWE-185 Incorrect Regular Expression

Affected Products

Product	Versions
ConsulHashiCorp	1.9.0 to before 2.0.4Affected
Consul EnterpriseHashiCorp	1.9.0 to before 2.0.4Affectedfrom 1.21.18Not affectedfrom 1.22.12Not affected

References

https://discuss.hashicorp.com/t/hcsec-2026-37-consul-vulnerable-to-an-authorization-bypass-in-the-connect-service-mesh/77739

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