CVE-2026-87090: Consul vulnerable to an authorization bypass in the catalog node-write path

Severity: high (CVSS 8.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-10 · updated 2026-09-10
Weakness: CWE-863

Description

Consul and Consul Enterprise are vulnerable to an authorization bypass in the catalog node-write path that may allow an authenticated attacker to delete another node's catalog registration and take over its node identity. An attacker with a token granting node-write permission on any single node name may exploit this issue if they can obtain the node ID of a node they do not control. This vulnerability (CVE-2026-87090) 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 0.1.0 before 2.0.4 — fixed in 2.0.4
HashiCorp Consul Enterprise: from 0.1.0 before 2.0.4 — fixed in 2.0.4

How to fix

Upgrade to a fixed version: HashiCorp Consul 2.0.4; HashiCorp Consul Enterprise 2.0.4. Check the vendor advisory for mitigations.

References

https://discuss.hashicorp.com/t/hcsec-2026-34-consul-vulnerable-to-an-authorization-bypass-in-the-catalog-node-write-path/77736

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