CVE-2022-36103: Talos Linux is a Linux distribution built for Kubernetes deployments. Talos worker nodes use a join token to get accepted into the Talos cluster. Due ...

Description

Talos Linux is a Linux distribution built for Kubernetes deployments. Talos worker nodes use a join token to get accepted into the Talos cluster. Due to improper validation of the request while signing a worker node CSR (certificate signing request) Talos control plane node might issue Talos API certificate which allows full access to Talos API on a control plane node. Accessing Talos API with full level access on a control plane node might reveal sensitive information which allows full level access to the cluster (Kubernetes and Talos PKI, etc.). Talos API join token is stored in the machine configuration on the worker node. When configured correctly, Kubernetes workloads don't have access to the machine configuration, but due to a misconfiguration workload might access the machine configuration and reveal the join token. This problem has been fixed in Talos 1.2.2. Enabling the Pod Security Standards mitigates the vulnerability by denying hostPath mounts and host networking by default in the baseline policy. Clusters that don't run untrusted workloads are not affected. Clusters with correct Pod Security configurations which don't allow hostPath mounts, and secure access to cloud metadata server (or machine configuration is not supplied via cloud metadata server) are not affected.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.53%

40.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Siderolabs	Talos Linux	< 1.2.2

References

https://github.com/siderolabs/talos/commit/9eaf33f3f274e746ca1b442c0a1a0dae0cec088fPatch, Third Party Advisory
https://github.com/siderolabs/talos/releases/tag/v1.2.2Release Notes, Third Party Advisory
https://github.com/siderolabs/talos/security/advisories/GHSA-7hgc-php5-77qqMitigation, Third Party Advisory
https://github.com/siderolabs/talos/commit/9eaf33f3f274e746ca1b442c0a1a0dae0cec088fPatch, Third Party Advisory
https://github.com/siderolabs/talos/releases/tag/v1.2.2Release Notes, Third Party Advisory
https://github.com/siderolabs/talos/security/advisories/GHSA-7hgc-php5-77qqMitigation, Third Party Advisory

Timeline

Published: Sep 13, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-36103?

Talos Linux is a Linux distribution built for Kubernetes deployments. Talos worker nodes use a join token to get accepted into the Talos cluster. Due to improper validation of the request while signing a worker node CSR (certificate signing request) Talos control plane node might issue Talos API certificate which allows full access to Talos API on a control plane node. Accessing Talos API with full level access on a control plane node might reveal sensitive information which allows full level access to the cluster (Kubernetes and Talos PKI, etc.). Talos API join token is stored in the machine configuration on the worker node. When configured correctly, Kubernetes workloads don't have access to the machine configuration, but due to a misconfiguration workload might access the machine configuration and reveal the join token. This problem has been fixed in Talos 1.2.2. Enabling the Pod Security Standards mitigates the vulnerability by denying hostPath mounts and host networking by default in the baseline policy. Clusters that don't run untrusted workloads are not affected. Clusters with correct Pod Security configurations which don't allow hostPath mounts, and secure access to cloud metadata server (or machine configuration is not supplied via cloud metadata server) are not affected.

How severe is CVE-2022-36103?

CVE-2022-36103 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2022-36103?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.