{"id":"CVE-2021-47857","aliases":["BIT-moodle-2021-47857","EUVD-2026-3616","GHSA-px56-6vfj-h8xp"],"status":"published","title":"Moodle 3.10.3 - 'label' Persistent Cross Site Scripting","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.","severity":{"version":"4.0","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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00377,"percentile":0.32104,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-01-21T17:27:39Z","modified":"2026-10-24T10:30:50Z","affected":[{"source":"osv","ecosystem":"Bitnami","package":"moodle","ranges":[{"type":"SEMVER","events":[{"introduced":"3.10.3"},{"last_affected":"3.10.3"}]}]}],"products":[{"vendor":"moodle","product":"moodle"}],"references":[{"url":"https://www.exploit-db.com/exploits/49714","tags":["exploit","Exploit","Third Party Advisory","VDB Entry","advisory","evidence"]},{"url":"https://moodle.org/","tags":["product","Product","web"]},{"url":"https://www.vulncheck.com/advisories/moodle-label-persistent-cross-site-scripting","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-47857","tags":["web"]},{"url":"https://moodle.org"},{"url":"https://github.com/advisories/GHSA-px56-6vfj-h8xp"}],"sources":{"cve":[{"id":"CVE-2021-47857","title":"Moodle 3.10.3 - 'label' Persistent Cross Site Scripting","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.","status":"published","published":"2026-01-21T17:27:39.382Z","modified":"2026-03-05T01:28:54.718Z","cvss":[{"version":"4.0","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","level":"medium","assessor":"cna"},{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:32:56.308189Z"}],"euvd":[{"id":"EUVD-2026-3616","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.","status":"published","published":"2026-01-21T17:27:39Z","modified":"2026-03-05T01:28:54Z","cvss":[{"version":"4.0","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","level":"medium"}],"updated_at":"2026-11-02T19:48:09.897368Z"}],"ghsa":[{"id":"GHSA-px56-6vfj-h8xp","title":"Moodle 3.10.3 contains a persistent cross-site scripting vulnerability in the calendar event...","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.","status":"published","published":"2026-01-21T18:30:31Z","modified":"2026-01-21T18:30:38Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:05:50.792909Z"}],"nvd":[{"id":"CVE-2021-47857","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.","status":"published","published":"2026-01-21T18:16:16.567Z","modified":"2026-06-17T04:18:38.433Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:07:09.005706Z"}],"osv":[{"id":"CVE-2021-47857","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.","status":"published","published":"2026-01-21T18:16:16.567Z","modified":"2026-10-24T10:30:50.045219956Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:22.824781Z"},{"id":"BIT-moodle-2021-47857","title":"Moodle 3.10.3 - 'label' Persistent Cross Site Scripting","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.","status":"published","published":"2026-03-06T08:46:28.845Z","modified":"2026-09-10T16:01:43.396995373Z","updated_at":"2026-11-02T15:28:33.469426Z"}]}}