CVE-2026-45726: Omni Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-wv8c-6mx2-xf4j
CVSS 7.6
CWE-732 CWE-522 CWE-200
Published
Advisory Summary

CVE-2026-45726 is a HIGH (CVSS 7.6) remote code execution vulnerability (CWE-732: Incorrect Permission Assignment for Critical Resource) affecting Omni libraries in the Go ecosystem. The issue involves reader-level users can retrieve imported cluster ca keys via resourceservice. Remediation is available by upgrading affected packages to version 1.6.6, 1.7.3.

CVE-2026-45726 at a Glance

CVE Identifier CVE-2026-45726
GHSA Identifier GHSA-wv8c-6mx2-xf4j
Severity HIGH
CVSS v3.1 Base Score 7.6
CWE Classification CWE-732: Incorrect Permission Assignment for Critical Resource
Affected Product Omni
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.6

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

Attack Vector Adjacent (AV:A)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-45726

To remediate this vulnerability, upgrade all affected Omni 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/siderolabs/omni fixed: 1.6.6
Upgrade github.com/siderolabs/omni to 1.6.6
github.com/siderolabs/omni fixed: 1.7.3
Upgrade github.com/siderolabs/omni to 1.7.3
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/siderolabs/omni

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-45726, inspect your project dependencies for Omni:

inspect dependencies for github.com/siderolabs/omni

Analyze the terminal output to locate any version of Omni in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.6.6), 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-732: Incorrect Permission Assignment for Critical Resource, where the product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. In Omni, 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

## Summary Omni supports importing standalone Talos clusters. During this process, an ImportedClusterSecrets resource is created, which contains the full CA secrets bundle for the cluster being imported. If these secrets are not rotated by the importing actor, an authenticated Omni user with Reader access can read this resource and gain full access to the Talos, Kubernetes and etcd APIs of the cluster. ## Severity - **Attack Vector:** Adjacent: the attacker needs to be in the same network to be able to access Talos/Kubernetes APIs with the compromised keys. - **Attack Complexity:** High: the attacker needs a deep understanding of Omni's internals. The resource is only created for imported clusters, and is normally not represented to users via any high-level API. - **Privileges Required:** Low: the role `Reader` is sufficient for the attacker to be able to read an imported cluster's secrets. - **User Interaction:** Required: another user must have imported a cluster to Omni for this vulnerability to exist. - **Scope:** Changed: the leaked CA private keys let an attacker directly get full control on Kubernetes or Talos, beyond the limitations enforced by Omni. - **Confidentiality Impact:** High: full cluster CA private keys (Kubernetes, Talos, etcd, service account) are exposed. - **Integrity Impact:** High: with the CA keys the attacker has full control on Kubernetes and Talos of the compromised (imported) cluster, and modify the workloads on it. - **Availability Impact:** High: with the CA keys the attacker has full control on Kubernetes and Talos of the compromised (imported) cluster, and modify the workloads on it. ## Impact - Any Reader-level account can exfiltrate the complete CA private key hierarchy (Kubernetes CA, etcd CA, service account key) of the imported clusters whose secrets are not yet rotated ("tainted" imported clusters). - With the Kubernetes CA private key, an attacker can sign certificates for any Kubernetes user or group, including `system:masters`, achieving cluster-admin access to the imported cluster entirely outside Omni's control plane. - Impact scope extends beyond Omni to every Kubernetes workload, credential, and secret stored in the affected imported cluster. ## Credit This vulnerability was discovered and reported by [bugbunny.ai](https://bugbunny.ai).

CVE-2026-45726 Affected Omni Versions

2 component(s)
Fixed Versions:
1.6.61.7.3
Product / Package Ecosystem Affected Versions Fixed Version
github.com/siderolabs/omni
Go
≥ 1.3.0
< 1.6.6
1.6.6
github.com/siderolabs/omni
Go
≥ 1.7.0
< 1.7.3
1.7.3

References

Frequently Asked Questions

What is CVE-2026-45726?
CVE-2026-45726 is a security vulnerability in Omni involving Reader-level users can retrieve imported cluster CA keys via ResourceService under CWE-732: Incorrect Permission Assignment for Critical Resource.
Which Omni versions are affected?
Affected versions include releases prior to 1.6.6, 1.7.3 across affected packages: github.com/siderolabs/omni.
What version fixes CVE-2026-45726?
Upgrading to 1.6.6, 1.7.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/siderolabs/omni affected?
Yes, github.com/siderolabs/omni is affected in releases prior to 1.6.6, 1.7.3. Upgrade your dependency to 1.6.6, 1.7.3 or later.
What is the CVSS score of CVE-2026-45726?
CVE-2026-45726 has a CVSS v3.1 base score of 7.6 (HIGH) with vector string CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-45726?
CVE-2026-45726 is classified under CWE-732: Incorrect Permission Assignment for Critical Resource (The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.).
How can I check Go dependencies for CVE-2026-45726?
Run the dependency tree command: 'inspect dependencies for github.com/siderolabs/omni'. 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-wv8c-6mx2-xf4j",
  "modified" : "2026-06-05T15:26:24Z",
  "published" : "2026-06-05T15:26:24Z",
  "aliases" : [ "CVE-2026-45726" ],
  "summary" : "Omni: Reader-level users can retrieve imported cluster CA keys via ResourceService",
  "details" : "## Summary\n\nOmni supports importing standalone Talos clusters.\n\nDuring this process, an ImportedClusterSecrets resource is created, which contains the full CA secrets bundle for the cluster being imported.\n\nIf these secrets are not rotated by the importing actor, an authenticated Omni user with Reader access can read this resource and gain full access to the Talos, Kubernetes and etcd APIs of the cluster.\n\n## Severity\n\n- **Attack Vector:** Adjacent: the attacker needs to be in the same network to be able to access Talos/Kubernetes APIs with the compromised keys.\n- **Attack Complexity:** High: the attacker needs a deep understanding of Omni's internals. The resource is only created for imported clusters, and is normally not represented to users via any high-level API.\n- **Privileges Required:** Low: the role `Reader` is sufficient for the attacker to be able to read an imported cluster's secrets.\n- **User Interaction:** Required: another user must have imported a cluster to Omni for this vulnerability to exist.\n- **Scope:** Changed: the leaked CA private keys let an attacker directly get full control on Kubernetes or Talos, beyond the limitations enforced by Omni.\n- **Confidentiality Impact:** High: full cluster CA private keys (Kubernetes, Talos, etcd, service account) are exposed.\n- **Integrity Impact:** High: with the CA keys the attacker has full control on Kubernetes and Talos of the compromised (imported) cluster, and modify the workloads on it.\n- **Availability Impact:** High: with the CA keys the attacker has full control on Kubernetes and Talos of the compromised (imported) cluster, and modify the workloads on it.\n\n## Impact\n\n- Any Reader-level account can exfiltrate the complete CA private key hierarchy (Kubernetes CA, etcd CA, service account key) of the imported clusters whose secrets are not yet rotated (\"tainted\" imported clusters).\n- With the Kubernetes CA private key, an attacker can sign certificates for any Kubernetes user or group, including `system:masters`, achieving cluster-admin access to the imported cluster entirely outside Omni's control plane.\n- Impact scope extends beyond Omni to every Kubernetes workload, credential, and secret stored in the affected imported cluster.\n\n## Credit\nThis vulnerability was discovered and reported by [bugbunny.ai](https://bugbunny.ai).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/siderolabs/omni"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.3.0"
      }, {
        "fixed" : "1.6.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/siderolabs/omni"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.7.0"
      }, {
        "fixed" : "1.7.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siderolabs/omni/security/advisories/GHSA-wv8c-6mx2-xf4j"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siderolabs/omni"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siderolabs/omni/releases/tag/v1.6.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siderolabs/omni/releases/tag/v1.7.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-522", "CWE-732" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-05T15:26:24Z",
    "nvd_published_at" : null
  }
}