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Security Bulletin: L7 intention authorization bypass via custom public listener

Security Bulletin


Summary

Consul Community Edition and Consul Enterprise 1.20.1 through 2.0.2 are vulnerable to an L7 intention authorization bypass when a service proxy is configured with a custom public listener. An authenticated mesh workload may reach HTTP paths that are blocked by a path-based deny intention. This vulnerability, CVE-2026-15970, is fixed in Consul 2.0.3 and Consul Enterprise 1.21.17, 1.22.11, and 2.0.3.

Vulnerability Details

CVEID: CVE-2026-15970
DESCRIPTION: When Consul generates xDS configuration for a service using a custom public listener, it injected the L7 intention enforcement filter but did not apply the same HTTP request normalization settings used by standard listeners. As a result, path-based intention rules on custom listeners could be evaluated against requests in a form that allowed them to be bypassed. An authenticated mesh workload that is already permitted to connect to the destination service may exploit this to reach paths that are blocked by a deny intention. Only services configured with envoy_public_listener_json and path-based L7 deny intentions are affected; services using the standard listener configuration are not affected.
CWE: CWE-647: Non-Canonical URL Authorization
CVSS Source: HashiCorp Inc.
CVSS Base score: 4.2
CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N)

Affected Products and Versions

Affected Product(s)Version(s)
Consul Community Editionaffected from 1.20.1 up to 2.0.3
Consul Enterpriseaffected from 1.20.1 up to 2.0.3, unaffected from 1.21.17, 1.22.11

Remediation/Fixes

Customers should evaluate the risk associated with this issue and consider upgrading to Consul 2.0.3 or Consul Enterprise 1.21.17, 1.22.11, or 2.0.3.

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References

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Acknowledgement

This issue was reported by Erichen.

Change History

07 Aug 2026: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
07 August 2026

Initial Publish date:
07 August 2026

UID

ibm17283000