CVE-2021-36401

Name: CVE-2021-36401
Creator: NVD / NIST
Published: 2023-03-06T22:15:09.62+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.8/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2021-36401 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. In Moodle, ID numbers exported in HTML data formats required additional sanitizing to prevent a local stored XSS risk.. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

In Moodle, ID numbers exported in HTML data formats required additional sanitizing to prevent a local stored XSS risk.

Metrics

CVSS 3.1

4.8/10

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

EPSS Probability

0.53%

40.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Moodle	Moodle	< 3.9.8
Moodle	Moodle	>= 3.10.0, < 3.10.5
Moodle	Moodle	>= 3.11.0, < 3.11.1

References

https://moodle.org/mod/forum/discuss.php?d=424807Patch, Vendor Advisory
https://moodle.org/mod/forum/discuss.php?d=424807Patch, Vendor Advisory

Timeline

Published: Mar 6, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36401?

In Moodle, ID numbers exported in HTML data formats required additional sanitizing to prevent a local stored XSS risk.

How severe is CVE-2021-36401?

CVE-2021-36401 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36401?

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-2021-36401?

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

Scan your code now

Source: NVD / NIST