# CVE-2026-63121: Kubewarden trusted-repos-policy: uppercase registry host bypasses registry/image deny rules

Status: published. Published: 2026-10-30. Updated: 2026-11-05.

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.

## Remediation

- fix: trusted-repos-policy (kubewarden): GitHub reports patched versions 2.1.2. Check the advisory for the affected release branch. (source: GitHub GHSA-8p62-9vh2-272p) — https://github.com/kubewarden/policies/security/advisories/GHSA-8p62-9vh2-272p

## Affected products and versions

- kubewarden / policies: < 2.1.2 (affected). Source: CNA: GitHub_M
-  / trusted-repos-policy (trusted-repos-policy): 2.1.1 (affected, GitHub advisory range). Source: GitHub GHSA-8p62-9vh2-272p

## Severity and prioritization

- CVSS 3.1: 6.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L; source: CNA: GitHub_M

- CVSS 3.1: 6.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.19% as of 2026-11-04; percentile 9.09%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-178

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/kubewarden/policies/security/advisories/GHSA-8p62-9vh2-272p (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/kubewarden/policies/commit/bc5597fcbbb0bc464b714ca7ff645c9743dea41b (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/kubewarden/policies/tree/trusted-repos-policy/v2.1.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/kubewarden/policies/commit/bc5597fcbbb0bc464b714ca7ff645c9743dea41b (security-advisories@github.com)

- https://github.com/kubewarden/policies/security/advisories/GHSA-8p62-9vh2-272p (security-advisories@github.com)

- https://github.com/kubewarden/policies/tree/trusted-repos-policy/v2.1.2 (security-advisories@github.com)

- https://github.com/kubewarden/policies/security/advisories/GHSA-8p62-9vh2-272p (GitHub Security Advisories; advisory)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-63121; retrieved 2026-11-05; source updated 2026-11-05

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63121; retrieved 2026-11-03; source updated 2026-11-02

- GitHub Security Advisories: https://github.com/kubewarden/policies/security/advisories/GHSA-8p62-9vh2-272p; retrieved 2026-11-04; source updated 2026-07-15

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-63121; retrieved 2026-11-05; source updated Not reported

Revision: d30737234251a69aed9057e5c7e5b17c5e7d83215013a5f8bb1eb1d416b960a1

Canonical: https://y2.dev/cve/CVE-2026-63121

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