CVE-2024-26151: The `mjml` PyPI package, found at the `FelixSchwarz/mjml-python` GitHub repo, is an unofficial Python port of

This month

HIGH 8.2DOWNGRADE

CVE-2024-26151 is a high-severity flaw (CVSS 8.2) affecting mjml-python. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 inje

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-20, CWE-79
Published	2024-02-22
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: felixschwarz

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-02-22 19:15 UTCPublished CVE record published
2026-06-17 07:17 UTCUpdated Record last modified

felixschwarz mjml-python DOWNGRADE

Affected: 0.10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.10.0

1. Check installed version

apt-cache policy mjml-python || rpm -q mjml-python || mjml-python --version

2. No fixed release: DOWNGRADE to a release before 0.10.0 (Debian / Ubuntu)

apt-cache madison mjml-python sudo apt install mjml-python=<VERSION_BEFORE_0.10.0> sudo apt-mark hold mjml-python

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mjml-python sudo dnf downgrade mjml-python-<VERSION_BEFORE_0.10.0> sudo dnf versionlock add mjml-python

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-26151?

mjml-python: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-26151 being exploited?

CVE-2024-26151 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-26151 affect?

CVE-2024-26151 affects mjml-python. Severity is high (CVSS 8.2). 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

How urgent is CVE-2024-26151?

Priority 46/100. High severity; Public exploit reference

Software pages

Python vulnerabilities · GitHub vulnerabilities · PyPI packages vulnerabilities

References

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