GHSA-45h5-66jx-r2wf is a medium-severity (CVSS 4.5) CWE-36 vulnerability in mjml. A fix is available for mjml — see the affected versions and patch details below.
MJML allows mj-include directory traversal due to an incomplete fix for CVE-2020-12827
Exploitation Status
No confirmed exploitation observed yet
- 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 GHSA-45h5-66jx-r2wf.
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
GHSA-45h5-66jx-r2wf 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 377,166 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
mjmlnpmDescription
MJML before 5.0.0-alpha.9 allows mj-include directory traversal to test file existence and (in the type="css" case) read files. NOTE: this issue exists because of an incomplete fix for CVE-2020-12827.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mjml | all versions | 5.0.0-alpha.9npm install mjml@5.0.0-alpha.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mjml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mjml to 5.0.0-alpha.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-45h5-66jx-r2wf 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 GHSA-45h5-66jx-r2wf can be triaged on real exposure rather than presence alone.
Tailored to GHSA-45h5-66jx-r2wf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-45h5-66jx-r2wf in your dependencies?
O3 Security finds GHSA-45h5-66jx-r2wf across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.