Incorrect authorization in Cilium - CVE-2026-53935
Published: November 9, 2026
Vulnerability identifier: #VU162614
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-53935
CWE-ID: CWE-863
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a privileged adjacent-network attacker with permission to create CiliumLocalRedirectPolicies to hijack traffic destined for Services in any namespace.
The vulnerability exists due to missing namespace restrictions on the addressMatcher configuration in CiliumLocalRedirectPolicy when an arbitrary ClusterIP is specified. A privileged adjacent-network attacker can create a policy targeting another namespace's Service ClusterIP to redirect its traffic, bypassing the namespace isolation enforced by serviceMatcher.
Affected software
Cilium
How to mitigate CVE-2026-53935
Install security update from vendor's website.
Cilium - addressed in versions 1.17.16, 1.18.10, 1.19.4