CVE-2021-47857

HIGH 7.2

Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

CVSS Score

7.2

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	moodle
Product	moodle
Published	Jan 21, 2026
Last Updated	Mar 5, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

Moodle / Moodle

3.10.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

exploit-db.com: https://www.exploit-db.com/exploits/49714 moodle.org: https://moodle.org/ vulncheck.com: https://www.vulncheck.com/advisories/moodle-label-persistent-cross-site-scripting

Credits

Vincent666 ibn Winnie