Vulnerability · Published Oct 30, 2026 · Assigned by GitHub_M
CVE-2026-63121Kubewarden trusted-repos-policy: uppercase registry host bypasses registry/image deny rules
Medium 6.3
In plain English
A medium-severity security flaw in policies from kubewarden. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| kubewarden | policies | < 2.1.2 |
Weakness: CWE-178 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L