CVE-2021-28001

Name: CVE-2021-28001
Creator: NVD / NIST
Published: 2021-08-19T14:39:31.717+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 1.02%

Last modified Jun 17, 2026

CVE-2021-28001 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. A cross-site scripting vulnerability was discovered in the Comments parameter in Textpattern CMS 4.8.4 which allows remote attackers to execute arbitrary code via a crafted payload entered into the URL field. The vulnerability is triggered by users visiting https://site.com/articles/welcome-to-your-site#comments-head.. EPSS estimates a 1.02% chance of exploitation in the next 30 days.

Description

A cross-site scripting vulnerability was discovered in the Comments parameter in Textpattern CMS 4.8.4 which allows remote attackers to execute arbitrary code via a crafted payload entered into the URL field. The vulnerability is triggered by users visiting https://site.com/articles/welcome-to-your-site#comments-head.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

1.02%

59.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Textpattern	Textpattern	4.8.4

References

https://www.exploit-db.com/exploits/49616Exploit, Third Party Advisory, VDB Entry
https://www.exploit-db.com/exploits/49616Exploit, Third Party Advisory, VDB Entry

Timeline

Published: Aug 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28001?

How severe is CVE-2021-28001?

CVE-2021-28001 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28001?

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-2021-28001?

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

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Source: NVD / NIST