CVE-2022-36103 is a high-severity (CVSS 7.2) CWE-732 vulnerability in github.com/talos-systems/talos. A fix is available for github.com/talos-systems/talos — see the affected versions and patch details below.
Talos worker join token can be used to get elevated access level to the Talos API
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-36103.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-36103 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/talos-systems/talosReal-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
Impact
Talos worker nodes use a join token to get accepted into the Talos cluster. A misconfigured Kubernetes environment may allow workloads to access the join token of the worker node. A malicious workload could then use the join token to construct a Talos CSR (certificate signing request). Due to improper validation while signing a worker node CSR, a Talos control plane node might issue a Talos certificate which allows full access to the Talos API to a worker node that presented a maliciously constructed CSR. Accessing the Talos API with full access on a control plane node might reveal sensitive information, which could allow full-level access to the cluster (Kubernetes and Talos PKI, etc.)
In order to exploit the weakness, a Kubernetes workload would need to access the join token, and then construct a specific kind of Talos CSR in order to obtain a privileged certificate. The Talos API join token is stored in the machine configuration on the worker node. When configured correctly, Kubernetes workloads do not have access to the machine configuration, and thus cannot access the token, nor acquire elevated privileges.
It is possible that users have misconfigured Kubernetes in such a way as to allow a workload to access the machine configuration and reveal the join token. Misconfigurations that may allow the machine configuration to be accessed on a worker node by the Kubernetes workload are:
- allowing a
hostPathmount to mount the machine config directly from the host filesystem (hostPathmounts should not be allowed for untrusted workloads, and are disabled by default in recent versions of Talos.) - reading machine configuration from a cloud metadata server from Kubernetes pods with host networking (on cloud platforms, when machine config is stored in the cloud metadata server, and the cloud metadata server doesn't provide enough protection to prevent access from non-host workloads)
Patches
The problem was fixed in Talos 1.2.2.
Workarounds
Enabling the Pod Security Standards mitigates the vulnerability by denying hostPath mounts and host networking by default in the baseline policy. Talos enables Pod Security Admission plugin by default since Talos v1.1.0.
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.
References
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/talos-systems/talos | all versions | 1.2.2go get github.com/talos-systems/talos@v1.2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/talos-systems/talos, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/talos-systems/talos to 1.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-36103 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-36103 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-36103. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-36103 in your dependencies?
O3 Security finds CVE-2022-36103 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.