7.1High

CVE-2026-88021

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.

What this means for your business

  • An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
7.1 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Weakness
CWE-185
Assigned by
security@hashicorp.com

Dates

Published
2026-09-10
Last modified
2026-09-10
Sources
NVD

References