CVE-2021-27912: XSS vulnerability on asset view

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-08-30 · updated 2026-06-17
Weakness: CWE-79

Description

Mautic versions before 3.3.4/4.0.0 are vulnerable to an inline JS XSS attack when viewing Mautic assets by utilizing inline JS in the title and adding a broken image URL as a remote asset. This can only be leveraged by an authenticated user with permission to create or edit assets.

Affected products

Mautic: before 3.3.4; 4.0.0-alpha1, 4.0.0-beta, 4.0.0-rc — fixed in 3.3.4

How to fix

Upgrade to a fixed version: Mautic 3.3.4. Check the vendor advisory for mitigations.

References

https://github.com/mautic/mautic/security/advisories/GHSA-rh5w-82wh-jhr8
https://github.com/mautic/mautic/security/advisories/GHSA-rh5w-82wh-jhr8

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