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TI-2021-22471 Aliases CVE-2021-47857GHSA-px56-6vfj-h8xp

Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

Priority MEDIUM 56CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00377 31st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA and NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MoodleMoodle3.10.3—No fix listedCNA
  • Moodle VendorMoodle Affected 3.10.3 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:moodle:moodle:3.10.3:*:*:*:*:*:*:*3.10.3VulnerableMoodle
  • cpe:2.3:a:moodle:moodle:3.10.3:*:*:*:*:*:*:* Versions 3.10.3 Vulnerable ·Moodle

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47857
  2. 2026-10-03 Alias added: GHSA-px56-6vfj-h8xp

References

Exploit 1

Other 1

  • TI-2024-22468 moodle: unsafe direct use of $_SERVER['HTTP_REFERER'] in admin/tool/mfa/index.php CVSS 3.1CRITICAL 9.8
  • TI-2021-14741 In Moodle, an SQL injection risk was identified in the library fetching a user's recent courses. CVSS 3.1CRITICAL 9.8
  • TI-2024-29071 Moodle: remote code execution via calculated question types CVSS 3.1HIGH 8.1
  • TI-2016-06653 Moodle 3.1.2 allows remote attackers to obtain sensitive information via unspecified… CVSS 3.1HIGH 7.5
  • TI-2022-00259 SQL injection in moodle CVSS 3.1CRITICAL 9.8
  • TI-2022-16116 Path traversal in Moodle CVSS 3.1HIGH 7.5
See all 636 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences