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GHSA-86pv-95mj-7w5f

HighCVSS 8.2 / 10
Published Sep 1, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

Impact

Insufficient sanitization / filtering allows for arbitrary JavaScript Injection in Mautic using the bounce management callback function. The values submitted in the "error" and "error_related_to" parameters of the POST request of the bounce management callback will be permanently stored and executed once the details page of an affected lead is opened by a Mautic user.

An attacker with access to the bounce management callback function (identified with the Mailjet webhook, but it is assumed this will work uniformly across all kinds of webhooks) can inject arbitrary JavaScript Code into the "error" and "error_related_to" parameters of the POST request (POST /mailer/<product / webhook>/callback). It is noted that there is no authentication needed to access this function.

The JavaScript Code is stored permanently in the web application and executed every time an authenticated user views the details page of a single contact / lead in Mautic. This means, arbitrary code can be executed to, e.g., steal or tamper with information.

Patches

Upgrade to 3.3.4 or 4.0.0

Workarounds

No

References

https://github.com/mautic/mautic/releases/tag/3.3.4 https://github.com/mautic/mautic/releases/tag/4.0.0

For more information

If you have any questions or comments about this advisory:

Risk Scores
Base Score
8.2

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a low impact on the confidentiality of the information. There is a high impact on the integrity of the data.

Threat Intelligence
7.5

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.70%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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