How severe is CVE-2026-45726?

CVE-2026-45726 has a CVSS score of 7.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-45726?

CVE-2026-45726 affects the following packages: github.com/siderolabs/omni (Go), github.com/siderolabs/omni (Go). Ecosystems affected: Go.

How do I fix CVE-2026-45726?

Update github.com/siderolabs/omni to 1.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45726 is resolved across your whole dependency graph.

How do I detect CVE-2026-45726 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siderolabs/omni. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-45726 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-45726?

O3 pinpoints whether CVE-2026-45726 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-45726 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-45726 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-45726 published, and has it been updated?

CVE-2026-45726 was published on June 5, 2026 and was last updated on June 25, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2026-45726

HIGH

CVE-2026-45726 is a high-severity (CVSS 7.6) vulnerability in github.com/siderolabs/omni. O3 Security confirms whether CVE-2026-45726 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Omni: Reader-level users can retrieve imported cluster CA keys via ResourceService

Also known asGO-2026-5725

Published

Jun 5, 2026

Updated

Jun 25, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Jun 25, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

2 pkgs affected

🐹github.com/siderolabs/omni🐹github.com/siderolabs/omni

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/siderolabs/omni`	≥ 1.3.0&&< 1.6.6	1.6.6
🐹Go	`github.com/siderolabs/omni`	≥ 1.7.0&&< 1.7.3	1.7.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siderolabs/omni. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/siderolabs/omni to 1.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45726 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-45726 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-45726. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## 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:

O3 Security · Impact-Aware SCA

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