CVE-2021-47857

Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

Published Jan 21, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:moodle:moodle:3.10.3:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Moodle
Moodle moodle
Vendors & Products Moodle
Moodle moodle
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Moodle 3.10.3 - 'label' Persistent Cross Site Scripting
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Mar 5, 2026, 1:28 AM
Reserved
Jan 14, 2026, 5:11 PM
Status
Analyzed
Published
Jan 21, 2026, 6:16 PM
Modified
Jun 17, 2026, 4:18 AM