CVE-2021-35210

Name: CVE-2021-35210
Creator: NVD / NIST
Published: 2021-06-23T11:15:08.17+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.74%

Last modified Jun 17, 2026

CVE-2021-35210 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Contao 4.5.x through 4.9.x before 4.9.16, and 4.10.x through 4.11.x before 4.11.5, allows XSS. It is possible to inject code into the tl_log table that will be executed in the browser when the system log is called in the back end.. EPSS estimates a 0.74% chance of exploitation in the next 30 days.

Description

Contao 4.5.x through 4.9.x before 4.9.16, and 4.10.x through 4.11.x before 4.11.5, allows XSS. It is possible to inject code into the tl_log table that will be executed in the browser when the system log is called in the back end.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.74%

49.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Contao	Contao	>= 4.5.0, < 4.9.16
Contao	Contao	>= 4.10.0, < 4.11.5

References

https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021.htmlVendor Advisory
https://github.com/contao/contao/security/advisories/GHSA-h58v-c6rf-g9f7Third Party Advisory
https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021.htmlVendor Advisory
https://github.com/contao/contao/security/advisories/GHSA-h58v-c6rf-g9f7Third Party Advisory

Timeline

Published: Jun 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-35210?

How severe is CVE-2021-35210?

CVE-2021-35210 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.74% probability of exploitation in the next 30 days.

How do I fix CVE-2021-35210?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-35210?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST