High severity · published Sep 10, 2026
CVE-2026-88021
Consul vulnerable to an authorization bypass in the Connect service mesh
7.1
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
Consul · HashiCorp
1.9.0 before 2.0.4 · source: vendor
CE
Consul Enterprise · HashiCorp
1.9.0 before 2.0.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88021
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-88021
discuss.hashicorp.com
https://discuss.hashicorp.com/t/hcsec-2026-37-consul-vulnerable-to-an-authorization-bypass-in-the-connect-service-mesh/77739
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