Consul: Improper Handling of Case Sensitivity
CVE-2026-105608 is a high-severity improper handling of case sensitivity vulnerability in Consul from HashiCorp, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.1.0 as the first without the flaw, so updating Consul to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Consul to 2.1.0 or a later version.
- Update Consul Enterprise to 2.1.0 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| HashiCorp | Consul | 2.0.4 up to, but not including, 2.1.0 | 2.1.0 |
| HashiCorp | Consul Enterprise | 2.0.4 up to, but not including, 2.1.0 | 2.1.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (hashicorp.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Case Sensitivity
The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.
How developers prevent this class of flaw
- Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
More Improper Handling of Case Sensitivity vulnerabilities (CWE-178)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Other references
Other vulnerabilities in Consul
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
- 8.3 High severity
- 7.5 High severity
- 7.3 High severity
Recent Improper Handling of Case Sensitivity vulnerabilities
- 8.2 High severity
- 7.5 High severity
- 7.2 High severity
- 7.2 High severity
- 8.1 High severity
- 8.4 High severity
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