CVE-2024-26151

Potentially untrusted input is rendered as HTML in final output

MEDIUM
5.4
CVSS Score
Published: February 22, 2024 at 06:37 PM UTC
Updated: June 17, 2026 at 07:17 AM UTC
1 product affected across 1 vendorMjml Python

Using mjml-python by FelixSchwarz?

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.6%
SSVC
PoC

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 `&lt;script&gt;` 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.11.00.10.0= 0.10.0
Affected range stops below 0.11.0, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20CWE-79

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