CVE-2026-29773: Kubewarden Cross-namespace Data Exfiltration Vulnerability

MODERATE
Advisory Identifier: GHSA-6r7f-3fwq-hq74
CVSS 4.3
CWE-863
Published
Advisory Summary

CVE-2026-29773 is a MODERATE (CVSS 4.3) cross-namespace data exfiltration vulnerability (CWE-863: Incorrect Authorization) affecting Kubewarden libraries in the Go ecosystem. The issue involves cross-namespace data exfiltration via deprecated host callback binding. Remediation is available by upgrading affected packages to version 1.33.0.

CVE-2026-29773 at a Glance

CVE Identifier CVE-2026-29773
GHSA Identifier GHSA-6r7f-3fwq-hq74
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-863: Incorrect Authorization
Affected Product Kubewarden
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-29773

To remediate this vulnerability, upgrade all affected Kubewarden dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/kubewarden/kubewarden-controller fixed: 1.33.0
Upgrade github.com/kubewarden/kubewarden-controller to 1.33.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/kubewarden/kubewarden-controller

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-29773, inspect your project dependencies for Kubewarden:

inspect dependencies for github.com/kubewarden/kubewarden-controller

Analyze the terminal output to locate any version of Kubewarden in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.33.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Kubewarden, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact Kubewarden is a policy engine for Kubernetes. Kubewarden cluster operators can grant permissions to users to deploy namespaced AdmissionPolicies and AdmissionPolicyGroups in their Namespaces. One of Kubewarden promises is that configured users can deploy namespaced policies in a safe manner, without privilege escalation. An attacker with privileged "AdmissionPolicy" create permissions (which isn't the default) could make use of 3 deprecated host-callback APIs: `kubernetes/ingresses`, `kubernetes/namespaces`, `kubernetes/services`. The attacker can craft a policy that exercises these deprecated API calls and would allow them read access to Ingresses, Namespaces, and Services resources respectively. This attack is read-only, there is no write capability and no access to Secrets, ConfigMaps, or other resource types beyond these three. The attacker could read for example: - Namespace names and labels. - Services across all namespaces with ClusterIPs and ports to reveal cluster internal topology. - Ingresses across all namespaces with hostnames and routing rules. ### Patches The vulnerable, already deprecated host-capabilities (`kubernetes/ingresses`, `kubernetes/namespaces`, `kubernetes/services`) have been removed. The removed calls were not being exercised by any Kubewarden SDK. These host-callbacks had already been superseded for a long time by `kubewarden/kubernetes/list_resources_by_namespace`, `kubewarden/kubernetes/list_resources`, and `kubewarden/kubernetes/get_resource`. They provide similar capabilities while being more fine-grained, performant, and gated through our context-aware permissions feature. These current host-capabilities are part of the Kubernetes capabilities listed in our [docs](https://docs.kubewarden.io/reference/spec/host-capabilities/kubernetes). ### Workarounds Kubewarden operators can update the policy-server image used by their PolicyServers to tag `:v1.33.0`. Alternatively, Kubewarden operators can temporarily reduce the permissions of users to prevent them from creating or updating existing namespaced AdmissionPolicies or AdmissionPolicyGroups.

CVE-2026-29773 Affected Kubewarden Versions

1 component(s)
Fixed Versions:
1.33.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/kubewarden/kubewarden-controller
Go
< 1.33.0
1.33.0

References

Frequently Asked Questions

What is CVE-2026-29773?
CVE-2026-29773 is a security vulnerability in Kubewarden involving Cross-namespace data exfiltration via deprecated host callback binding under CWE-863: Incorrect Authorization.
Which Kubewarden versions are affected?
Affected versions include releases prior to 1.33.0 across affected packages: github.com/kubewarden/kubewarden-controller.
What version fixes CVE-2026-29773?
Upgrading to 1.33.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/kubewarden/kubewarden-controller affected?
Yes, github.com/kubewarden/kubewarden-controller is affected in releases prior to 1.33.0. Upgrade your dependency to 1.33.0 or later.
What is the CVSS score of CVE-2026-29773?
CVE-2026-29773 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-29773?
CVE-2026-29773 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check Go dependencies for CVE-2026-29773?
Run the dependency tree command: 'inspect dependencies for github.com/kubewarden/kubewarden-controller'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6r7f-3fwq-hq74",
  "modified" : "2026-03-10T18:43:12Z",
  "published" : "2026-03-09T17:28:38Z",
  "aliases" : [ "CVE-2026-29773" ],
  "summary" : "Kubewarden: Cross-namespace data exfiltration via deprecated host callback binding",
  "details" : "### Impact\n\nKubewarden is a policy engine for Kubernetes. Kubewarden cluster operators can grant permissions to users to deploy namespaced AdmissionPolicies and AdmissionPolicyGroups in their Namespaces. One of Kubewarden promises is that configured users can deploy namespaced policies in a safe manner, without privilege escalation.\n\nAn attacker with privileged \"AdmissionPolicy\" create permissions (which isn't the default) could make use of 3 deprecated host-callback APIs: `kubernetes/ingresses`, `kubernetes/namespaces`, `kubernetes/services`.\nThe attacker can craft a policy that exercises these deprecated API calls and would allow them read access to Ingresses, Namespaces, and Services resources respectively.\n\nThis attack is read-only, there is no write capability and no access to Secrets, ConfigMaps, or other resource types beyond these three. The attacker could read for example:\n- Namespace names and labels.\n- Services across all namespaces with ClusterIPs and ports to reveal cluster internal topology.\n- Ingresses across all namespaces with hostnames and routing rules.\n\n### Patches\nThe vulnerable, already deprecated host-capabilities (`kubernetes/ingresses`, `kubernetes/namespaces`, `kubernetes/services`)\nhave been removed.\n\nThe removed calls were not being exercised by any Kubewarden SDK.\n\nThese host-callbacks had already been superseded for a long time by `kubewarden/kubernetes/list_resources_by_namespace`, `kubewarden/kubernetes/list_resources`, and `kubewarden/kubernetes/get_resource`. They provide similar capabilities while being more fine-grained, performant, and gated through our context-aware permissions feature. These current host-capabilities are part of the Kubernetes capabilities listed in our [docs](https://docs.kubewarden.io/reference/spec/host-capabilities/kubernetes).\n\n### Workarounds\nKubewarden operators can update the policy-server image used by their PolicyServers to tag `:v1.33.0`.\nAlternatively, Kubewarden operators can temporarily reduce the permissions of users to prevent them from creating or updating existing namespaced AdmissionPolicies or AdmissionPolicyGroups.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/kubewarden/kubewarden-controller"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.33.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/kubewarden/kubewarden-controller/security/advisories/GHSA-6r7f-3fwq-hq74"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-29773"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubewarden/kubewarden-controller/pull/1519"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubewarden/kubewarden-controller/commit/4e41b60ae44902d82d94101bac93fb77cae65651"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kubewarden/kubewarden-controller"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-09T17:28:38Z",
    "nvd_published_at" : "2026-03-10T17:39:03Z"
  }
}