Vulnerability in Kubewarden Policies
CVE-2026-63121
Kubewarden policies is a collection of WebAssembly policies for securing and governing Kubernetes clusters. For versions provisionally classified as affected before 2.1.2, `trusted-repos-policy` compares an image's `registry` hostname against `reject lists` and `allow lists` case-sensitively even though `registry` DNS names are case-insensitive. An image with an uppercase or mixed-case `registry` hostname can miss a rejection rule for the equivalent lowercase host, so the admission policy accepts a resource whose container runtime pulls the same prohibited image. Only reject-list configurations have this bypass: allow-list configurations fail closed by over-denying differently cased hostnames. The security consequences depend on the configured rejection policy and deployment environment. This issue is fixed in version 2.1.2.
Published .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Kubewarden Policies — versions < 2.1.2
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-63121?
- CVE-2026-63121 is a medium-severity vulnerability in Kubewarden Policies, classified under Improper Handling of Case Sensitivity. CVSS score: 6.3/10. Published 2026-10-30.
- How severe is CVE-2026-63121?
- Medium severity. CVSS v3 base score is 6.3 out of 10.