CVE 2020-25700

In moodle, some database module web services allowed students to add entries within groups they did not belong to. Versions affected: 3.9 to 3.9.2, 3.8 to 3.8.5, 3.7 to 3.7.8, 3.5 to 3.5.14 and earlier unsupported versions. This is fixed in moodle 3.8.6, 3.7.9, 3.5.15, and 3.10.

See the CVE page on Mitre.org for more details.