CVE-2026-56742

Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces

Published Jul 15, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
Cilium is a networking, observability, and security solution. Prior to 1.17.17, 1.18.11, and 1.19.5, Cilium clusters using Gateway API allow users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism. Gateway API functionality is disabled by default. This issue is fixed in versions 1.17.17, 1.18.11, and 1.19.5.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-w7c2-w76w-5hmj Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cilium
Cilium cilium
Vendors & Products Cilium
Cilium cilium
Type Values Removed Values Added
Description Cilium is a networking, observability, and security solution. Prior to 1.17.17, 1.18.11, and 1.19.5, Cilium clusters using Gateway API allow users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism. Gateway API functionality is disabled by default. This issue is fixed in versions 1.17.17, 1.18.11, and 1.19.5.
Title Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 16, 2026, 12:57 PM
Reserved
Jun 22, 2026, 7:17 PM
Status
Analyzed
Published
Jul 15, 2026, 8:17 PM
Modified
Jul 17, 2026, 5:48 PM