In Zulip Server before 1.7.1, on a server with multiple realms, a vulnerability in the invitation system lets an authorized user of one realm on the server create a user account on any other realm.
Severity
CVSS 3.0
8.8 high
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
1.1% chance of exploitation in the next 30 days; higher than 65% of CVEs (scores of 2026-10-31)