Moodle 3.10.3 - 'label' Persistent Cross Site Scripting | Advisories

Advisories

Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

severity: medium
date: January 21, 2026
Affecting: Moodle 3.10.3
CVE: CVE-2021-47857
CWE: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSS: 5.1
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
References: ExploitDB-49714
Official Moodle Project Homepage
Credit: Vincent666 ibn Winnie
Description: Moodle 3.10.3 contains a persistent cross-site scripting vulnerability in the calendar event subtitle field that allows attackers to inject malicious scripts. Attackers can craft a calendar event with malicious JavaScript in the subtitle track label to execute arbitrary code when users view the event.