CVE-2024-26151: The `mjml` PyPI package, found at the `FelixSchwarz/mjml-python` GitHub repo, is an unofficial Python port of MJML, a markup language created by Mailj...

Description

The `mjml` PyPI package, found at the `FelixSchwarz/mjml-python` GitHub repo, is an unofficial Python port of MJML, a markup language created by Mailjet. All users of `FelixSchwarz/mjml-python` who insert untrusted data into mjml templates unless that data is checked in a very strict manner. User input like `<script>` would be rendered as `<script>` in the final HTML output. The attacker must be able to control some data which is later injected in an mjml template which is then send out as email to other users. The attacker could control contents of email messages sent through the platform. The problem has been fixed in version 0.11.0 of this library. Versions before 0.10.0 are not affected by this security issue. As a workaround, ensure that potentially untrusted user input does not contain any sequences which could be rendered as HTML.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.62%

45.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Felixschwarz	Mjml-Python	0.10.0

References

https://github.com/FelixSchwarz/mjml-python/commit/84c495da20a91640a1ca551ace17df7f3be644aaPatch
https://github.com/FelixSchwarz/mjml-python/commit/8d410b7a500703080bb14ed7e3d2663fe16767e6Patch
https://github.com/FelixSchwarz/mjml-python/issues/52Exploit, Issue Tracking
https://github.com/FelixSchwarz/mjml-python/releases/tag/v0.11.0Release Notes
https://github.com/FelixSchwarz/mjml-python/security/advisories/GHSA-578p-fxmm-6229Vendor Advisory
https://github.com/FelixSchwarz/mjml-python/commit/84c495da20a91640a1ca551ace17df7f3be644aaPatch
https://github.com/FelixSchwarz/mjml-python/commit/8d410b7a500703080bb14ed7e3d2663fe16767e6Patch
https://github.com/FelixSchwarz/mjml-python/issues/52Exploit, Issue Tracking
https://github.com/FelixSchwarz/mjml-python/releases/tag/v0.11.0Release Notes
https://github.com/FelixSchwarz/mjml-python/security/advisories/GHSA-578p-fxmm-6229Vendor Advisory
https://www.vicarius.io/vsociety/posts/cve-2024-26151-mjml-python-vulnerability-1Exploit, Third Party Advisory

Timeline

Published: Feb 22, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-26151?

The `mjml` PyPI package, found at the `FelixSchwarz/mjml-python` GitHub repo, is an unofficial Python port of MJML, a markup language created by Mailjet. All users of `FelixSchwarz/mjml-python` who insert untrusted data into mjml templates unless that data is checked in a very strict manner. User input like `<script>` would be rendered as `<script>` in the final HTML output. The attacker must be able to control some data which is later injected in an mjml template which is then send out as email to other users. The attacker could control contents of email messages sent through the platform. The problem has been fixed in version 0.11.0 of this library. Versions before 0.10.0 are not affected by this security issue. As a workaround, ensure that potentially untrusted user input does not contain any sequences which could be rendered as HTML.

How severe is CVE-2024-26151?

CVE-2024-26151 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.62% probability of exploitation in the next 30 days.

How do I fix CVE-2024-26151?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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