MJML allows mj-include directory traversal due to an incomplete fix for CVE-2020-12827

Description

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.

Recommendation

Update the mjml package to the latest compatible version. Followings are version details:

Affected version(s): < 5.0.0-alpha.9
Patched version(s): 5.0.0-alpha.9

References

GHSA-45h5-66jx-r2wf
CVE-2025-67898
CWE-36
CAPEC-310
OWASP 2021-A6

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See something that needs correcting? Let us knowUpdated June 26, 2026