CVE-2020-19049

Name: CVE-2020-19049
Creator: NVD / NIST
Published: 2021-08-31T14:15:25.39+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.72%

Last modified Jun 17, 2026

CVE-2020-19049 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Cross Site Scripting (XSS) in MyBB v1.8.20 allows remote attackers to inject arbitrary web script or HTML via the "Description" field found in the "Add New Forum" page by doing an authenticated POST HTTP request to '/Upload/admin/index.php?module=forum-management&action=add'.. EPSS estimates a 0.72% chance of exploitation in the next 30 days.

Description

Cross Site Scripting (XSS) in MyBB v1.8.20 allows remote attackers to inject arbitrary web script or HTML via the "Description" field found in the "Add New Forum" page by doing an authenticated POST HTTP request to '/Upload/admin/index.php?module=forum-management&action=add'.

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

0.72%

49.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mybb	Mybb	1.8.20

References

https://github.com/joelister/bug/issues/2Exploit, Third Party Advisory
https://github.com/joelister/bug/issues/2Exploit, Third Party Advisory

Timeline

Published: Aug 31, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-19049?

How severe is CVE-2020-19049?

CVE-2020-19049 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2020-19049?

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-2020-19049?

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

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Source: NVD / NIST