CVE-2026-88021 Consul vulnerable to an authorization bypass in the Connect service mesh
Attackers can bypass Connect service mesh authorization rules to access unauthorized destinations due to improper character escaping in generated RBAC policies.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-88021?
CVE-2026-88021 is a high-severity authentication bypass vulnerability in HashiCorp Consul, published on 10 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-185
Which versions are affected by CVE-2026-88021?
1 open source package ship an affected version, including consul.
| Package | Affected | Fixed in |
|---|---|---|
consul Bitnami | From 1.9.0 | 2.0.4 |
How do I fix CVE-2026-88021?
Upgrade consul to 2.0.4 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-88021 being exploited?
There is no known exploitation of CVE-2026-88021 in the wild and no public exploit code.
Sources
Also known as BIT-consul-2026-88021, GHSA-9p3q-p26q-fxxc, MINI-f6wr-99pf-h2vc, MINI-hv3j-3x8j-3q96, UBUNTU-CVE-2026-88021.