CVE-2021-27909: XSS vulnerability on password reset page

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-08-30 · updated 2026-06-17
Weakness: CWE-79

Description

For Mautic versions prior to 3.3.4/4.0.0, there is an XSS vulnerability on Mautic's password reset page where a vulnerable parameter, "bundle," in the URL could allow an attacker to execute Javascript code. The attacker would be required to convince or trick the target into clicking a password reset URL with the vulnerable parameter utilized.

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-32hw-3pvh-vcvc
https://github.com/mautic/mautic/security/advisories/GHSA-32hw-3pvh-vcvc

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