CVE-2021-35955

medium

Description

Contao >=4.0.0 allows backend XSS via HTML attributes to an HTML field. Fixed in 4.4.56, 4.9.18, 4.11.7.

References

https://github.com/advisories/GHSA-hr3h-x6gq-rqcp

https://github.com/contao/contao/security/advisories/GHSA-hr3h-x6gq-rqcp

https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-1756

https://contao.org/en/news/contao-4-9-16-and-4-11-5-are-available.html

Details

Source: Mitre, NVD

Published: 2021-08-12

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 3.5

Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N

Severity: Low

CVSS v3

Base Score: 4.8

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00557