CVE-2021-34254

Name: CVE-2021-34254
Creator: NVD / NIST
Published: 2021-06-28T16:15:08.743+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.71%

Last modified Jun 17, 2026

CVE-2021-34254 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.. EPSS estimates a 0.71% chance of exploitation in the next 30 days.

Description

Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.

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

0.71%

48.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Umbraco	Umbraco Cms	< 7.15.7

References

https://github.com/umbraco/Umbraco-CMS/issues/9782Issue Tracking, Third Party Advisory
https://github.com/umbraco/Umbraco-CMS/issues/9782Issue Tracking, Third Party Advisory

Timeline

Published: Jun 28, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34254?

Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.

How severe is CVE-2021-34254?

CVE-2021-34254 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34254?

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-2021-34254?

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

Scan your code now

Source: NVD / NIST