Summary
There are three potential attacks of arbitrary code injection vulnerability in the composite action at action.yml.
Details
The GitHub Action variables inputs.prek-version, inputs.extra_args, and inputs.extra-args can be used to execute arbitrary code in the context of the action.
PoC
- uses: j178/[email protected]
with:
prek-version: $(printenv >> $GITHUB_STEP_SUMMARY && echo "0.2.2")
extra_args: '&& echo "MY_SECRET with a character is: ${MY_SECRET:0:1}a${MY_SECRET:1}" >> $GITHUB_STEP_SUMMARY && echo ""'
env:
MY_SECRET: ${{ secrets.MY_SECRET }}
The previous example will print all the environment variables, and it will expose MY_SECRET environment variable value to the summary of the workflow. An attacker could potentially use this vector to compromise the security of the target repository, even passing unnotice because the action will run normally.
Impact
Critical, CWE-94
Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.
GHSA-PWF7-47C3-MFHX has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.0.6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-PWF7-47C3-MFHX? GHSA-PWF7-47C3-MFHX is a critical-severity code injection vulnerability in j178/prek-action (actions), affecting versions <= 1.0.5. It is fixed in 1.0.6. Untrusted input is evaluated as executable code within the application's runtime environment.
- How severe is GHSA-PWF7-47C3-MFHX? GHSA-PWF7-47C3-MFHX has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of j178/prek-action are affected by GHSA-PWF7-47C3-MFHX? j178/prek-action (actions) versions <= 1.0.5 is affected.
- Is there a fix for GHSA-PWF7-47C3-MFHX? Yes. GHSA-PWF7-47C3-MFHX is fixed in 1.0.6. Upgrade to this version or later.
- Is GHSA-PWF7-47C3-MFHX exploitable, and should I be worried? Whether GHSA-PWF7-47C3-MFHX is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-PWF7-47C3-MFHX is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-PWF7-47C3-MFHX? Upgrade
j178/prek-actionto 1.0.6 or later.