What’s Vulnerable › Vulnerabilities

CVE-2021-47857: Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-01-21 · updated 2026-06-17
• Weakness: CWE-79

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.

Affected products

• Moodle: 3.10.3

References

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

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