How severe is CVE-2023-23939?

CVE-2023-23939 has a CVSS score of 3.9/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-23939?

CVE-2023-23939 affects the following packages: Azure/setup-kubectl (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix CVE-2023-23939?

Update Azure/setup-kubectl to 3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-23939 is resolved across your whole dependency graph.

How do I detect CVE-2023-23939 in my GitHub Actions dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Azure/setup-kubectl. 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-2023-23939 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-2023-23939?

O3 pinpoints whether CVE-2023-23939 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-2023-23939 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-23939 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.

What is the EPSS score for CVE-2023-23939?

CVE-2023-23939 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-23939 published, and has it been updated?

CVE-2023-23939 was published on March 6, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-23939: Azure/setup-kubectl Privilege Escalation (Low 3…

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk28th percentile-0.53%

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.

Blast Radius

1 pkg affected

📦Azure/setup-kubectl

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

Description

Azure/setup-kubectl is a GitHub Action for installing Kubectl. This vulnerability only impacts versions before version 3. An insecure temporary creation of a file allows other actors on the Actions runner to replace the Kubectl binary created by this action because it is world writable. This Kubectl tool installer runs fs.chmodSync(kubectlPath, 777) to set permissions on the Kubectl binary, however, this allows any local user to replace the Kubectl binary. This allows privilege escalation to the user that can also run kubectl, most likely root. This attack is only possible if an attacker somehow breached the GitHub actions runner or if a user is utilizing an Action that maliciously executes this attack. This has been fixed and released in all versions v3 and later. 775 permissions are used instead. Users are advised to upgrade. There are no known workarounds for this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦GitHub Actions	`Azure/setup-kubectl`	all versions	3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Azure/setup-kubectl. 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 Azure/setup-kubectl to 3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-23939 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-2023-23939 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-2023-23939. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Azure/setup-kubectl is a GitHub Action for installing Kubectl. This vulnerability only impacts versions before version 3. An insecure temporary creation of a file allows other actors on the Actions runner to replace the Kubectl binary created by this action because it is world writable. This Kubectl tool installer runs `fs.chmodSync(kubectlPath, 777)` to set permissions on the Kubectl binary, however, this allows any local user to replace the Kubectl binary. This allows privilege escalation to the user that can also run kubectl, most likely root. This attack is only possible if an attacker som

O3 Security · Impact-Aware SCA

Is CVE-2023-23939 in your dependencies?

O3 detects CVE-2023-23939 across GitHub Actions dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2023-23939