{"id":"CVE-2021-20185","aliases":["BIT-moodle-2021-20185","GHSA-c3j6-33r4-89q3"],"url":"https://o3.security/vulnerability/CVE-2021-20185","summary":"Moodle Client side denial of service via personal message","details":"It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that messaging did not impose a character limit when sending messages, which could result in client-side (browser) denial of service for users receiving very large messages.","published":"2021-01-28T20:15:13.133Z","modified":"2026-07-08T22:14:54.483756Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"epss":{"score":0.01377,"percentile":0.70671,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":"3.5.16"},{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":"3.8.7"},{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":"3.9.4"},{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":"3.10.1"}],"fix":null,"references":[{"type":"FIX","url":"https://moodle.org/mod/forum/discuss.php?d=417168"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T22:14:54.483756Z"}}