CVE-2021-47857
mediumpriority · track · 24EPSS 0.004 · 32 %ileEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 1.2–7.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- BIT-moodle-2021-47857Moodle 3.10.3 - 'label' Persistent Cross Site Scripting2026-03-06vendor · osvUS
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.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2021-47857cnnvd
- https://moodle.org/cnnvd
- https://www.exploit-db.com/exploits/49714cnnvd
- https://www.vulncheck.com/advisories/moodle-label-persistent-cross-site-scriptingcnnvd
- https://moodle.org/enisa_euvd
- https://www.exploit-db.com/exploits/49714enisa_euvd
- https://www.vulncheck.com/advisories/moodle-label-persistent-cross-site-scriptingenisa_euvd
- https://moodle.org/Productnvd
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