Auth bypass in Red Hat Advanced Cluster Management For Kubernetes 2

CVE-2026-66878

A flaw was found in multicloud-operators-subscription. A privileged user, specifically a namespace administrator capable of creating Channel and Subscription resources, can exploit this vulnerability. By manipulating the Channel.Spec.SecretRef.Namespace field, the user can cause the system to copy sensitive Secret contents from other namespaces into their own, leading to information disclosure.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (39.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-66878: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-66878?
CVE-2026-66878 is a high-severity vulnerability in Red Hat Advanced Cluster Management For Kubernetes 2, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.7/10. Published 2026-08-12.
How severe is CVE-2026-66878?
High severity. CVSS v3 base score is 7.7 out of 10.