CVE-2022-39321 is a high-severity (CVSS 8.8) OS Command Injection vulnerability in actions/runner. A fix is available for actions/runner — see the affected versions and patch details below.
GitHub Actions Runner vulnerable to Docker Command Escaping
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-2022-39321.
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-2022-39321 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 378,567 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
actions/runner📦actions/runner📦actions/runner📦actions/runner📦actions/runnerReal-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
Impact
The actions runner invokes the docker cli directly in order to run job containers, service containers, or container actions. A bug in the logic for how the environment is encoded into these docker commands was discovered that allows an input to escape the environment variable and modify that docker command invocation directly. Jobs that use container actions, job containers, or service containers alongside untrusted user inputs in environment variables may be vulnerable.
Patches
The Actions Runner has been patched, both on github.com and hotfixes for GHES and GHAE customers. Please update to one of the following versions of the runner:
- 2.296.2
- 2.293.1
- 2.289.4
- 2.285.2
- 2.283.4
GHES and GHAE customers may want to patch their instance in order to have their runners automatically upgrade to these new runner versions.
Workarounds
You may want to consider removing any container actions, job containers, or service containers from your jobs until you are able to upgrade your runner versions.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the actions runner
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦GitHub Actions | actions/runner | ≥ 2.294.0&&< 2.296.2 | 2.296.2 |
| 📦GitHub Actions | actions/runner | ≥ 2.290.0&&< 2.293.1 | 2.293.1 |
| 📦GitHub Actions | actions/runner | ≥ 2.286.0&&< 2.289.4 | 2.289.4 |
| 📦GitHub Actions | actions/runner | ≥ 2.284.0&&< 2.285.2 | 2.285.2 |
| 📦GitHub Actions | actions/runner | all versions | 2.283.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for actions/runner, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update actions/runner to 2.296.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39321 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-2022-39321 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-39321. 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-2022-39321 in your dependencies?
O3 Security finds CVE-2022-39321 across GitHub Actions dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.