Security Bulletin
Summary
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.
Vulnerability Details
CVEID: CVE-2026-88021
DESCRIPTION: The authorization rules Consul generated for Connect service mesh intention enforcement did not correctly handle certain characters that may appear in service names, namespaces, and partitions. This could cause the generated rules to match a broader set of service identities than the operator intended, potentially allowing a caller to reach a destination service through an existing intention that was not created for them. This issue requires Connect service mesh to be enabled with active intentions. Deployments where catalog names do not contain the affected characters are not impacted in practice.
CWE: CWE-185: Incorrect Regular Expression
CVSS Source: HashiCorp Inc.
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Consul Community Edition | affected from 1.9.0 up to 2.0.4 |
| Consul Enterprise | affected from 1.9.0 up to 2.0.4, unaffected from 1.21.18, 1.22.12 |
Remediation/Fixes
Customers should evaluate the risk associated with this issue and consider upgrading to Consul 2.0.4 or Consul Enterprise 1.21.18, 1.22.12, or 2.0.4.
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References
Acknowledgement
This issue was reported to HashiCorp by Đoàn Thành.
Change History
10 Sep 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
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Document Location
Worldwide
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Document Information
Modified date:
10 September 2026
Initial Publish date:
10 September 2026
UID
ibm17287037