Description
An authentication rate-limit bypass in Zimbra Collaboration Suite 10.1.0 through 10.1.21 allows unauthenticated attackers to make repeated password guesses through GraphQL without incrementing Zimbra’s source-IP failure counter. GraphQL aliases allow multiple authentication attempts in one HTTP request.
References1
Metrics
- CVSS 3.1
-
3.7
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 26 · as of 11 November 2026
- CWE
- CWE-307
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.